Skip to content
Tool Comparisons — Head-to-Head Reviews

Tool Comparisons

Head-to-head breakdowns to help you pick the right tool.

Claude Opus 5
Claude Opus 5
9.7
VS
Kimi K3
Kimi K3
8.7

There is no overall winner here, and that is a conclusion rather than a hedge. On version 4.1 of the independent Artificial Analysis Intelligence Index, Claude Opus 5 scores 61 at max effort against Kimi K3’s 57 — four points on the rounded figures, 3.58 on the raw ones — while Kimi K3 costs a measured USD 0.72 per index task against USD 2.03, about 2.8 times less. Read that as a threshold rather than an average: if the hardest task in your workload sits above what a model scoring 57 can finish, the four points are the entire reason Opus 5 exists; if it sits below, and for most workloads it does, you are paying 2.8 times for headroom you never touch. The multiplier is also a property of a dial rather than of the two models — at Opus 5’s default high effort the comparison is 59 against 57 at about 1.5 times the cost, and at medium effort Opus 5 is cheaper than Kimi K3 while scoring one point lower. Opus 5 takes the capability ceiling, the stated May 2026 cutoff and long-prompt speed; Kimi K3 takes the cost, the responsiveness at very long context, and openness that is now delivered rather than promised: Moonshot published the weights on July 27, 2026, ungated, though under a custom Kimi K3 License with revenue-triggered commercial conditions rather than the Modified MIT widely reported. On the one independent bench covering both, hallucination rates are effectively tied at 50.07 and 50.94 percent, so Opus 5’s advantage there is accuracy, not fewer fabrications.

Grok 4.5
Grok 4.5
8.7
VS
Claude Fable 5
Claude Fable 5
9.6

A split verdict between the cheapest frontier challenger and one of the most capable models of 2026, and we will not fake a single overall winner. Claude Fable 5 is the capability and verification leader of this pair: it scores 59.9 on the Artificial Analysis Intelligence Index as of August 4, 2026 — second overall, behind only Claude Opus 5's 60.7 — holds a top-ten LMArena Elo, and posts a leading 95 percent on the independently verified vals.ai SWE-bench Verified suite, carries the larger 1,000,000-token context, and is available in the European Union. Grok 4.5 is the value and throughput leader: it costs $2 per million input tokens and $6 per million output tokens against Fable 5's $10 and $50 — roughly five times cheaper on input and about eight times cheaper on output — is measured at about $2.49 per task against roughly $11.80 for Fable 5, posts 64.4 on the Artificial Analysis Coding Agent Index v1.3 against 65.8 for Fable 5 — narrowly behind, not ahead — and is marketed as much faster, consistent with Anthropic's own Slower latency label on Fable 5. Grok 4.5 carries real caveats: it is not yet on the independent SWE-bench Verified or LMArena leaderboards, its AA-Omniscience factuality score of 26 comes with a 54 percent hallucination rate, and it is blocked in the European Union under the AI Act's systemic-risk provisions. Elon Musk's 'Opus-class, much faster' framing is partly supported on coding value and speed but overstated on general intelligence and reliability. Best for capability, independently verified coding, the larger context, and EU availability: Claude Fable 5. Best for cost, throughput, and speed outside the EU: Grok 4.5. No single overall winner — route capability-critical and EU-based work to Claude Fable 5, and cost-sensitive high-volume work outside the EU to Grok 4.5.

Grok 4.5
Grok 4.5
8.7
VS
GPT-5.5
GPT-5.5
8.6

A split verdict between the cheapest rate card and the most independently proven flagship, and we will not fake a single overall winner. Grok 4.5 reached public availability on July 9, 2026 as SpaceXAI's new flagship; GPT-5.5 has been OpenAI's established, still-active flagship since April 2026. On the rate card, Grok 4.5 is decisively cheaper: $2 per million input tokens and $6 per million output against GPT-5.5's $5 and $30 — less than half on both sides, verified on both vendors' own documentation — and Artificial Analysis measures its cost per task near the bottom of the frontier tier at about $2.49. SpaceXAI positions Grok 4.5 as 'Opus-class, much faster,' which we label as a vendor claim. GPT-5.5 answers with verified proof Grok 4.5 does not yet have: an independent SWE-bench Verified score of 82.6 percent on vals.ai, an LMArena Elo of 1481, a slightly higher Artificial Analysis Intelligence Index (55 to 54), more than double the context window (1,050,000 versus 500,000 tokens), a fuller native agentic tool stack, and EU availability that Grok 4.5 lacks under the AI Act. On independent agentic coding, both are charted and Grok 4.5 leads: Artificial Analysis lists it at 64.44 on its Coding Agent Index v1.3 through Grok Build at high effort, against GPT-5.5's best entry of 61.49 through Codex at xhigh — one effort step higher — a 2.95-point gap without a matched effort setting or a shared harness. Best for the lowest token price, low cost per task, and vendor-stated speed on high-volume, non-EU work: Grok 4.5. Best for independently verified capability, long context, EU deployment, and a mature ecosystem: GPT-5.5. No single overall winner — route cost-sensitive, high-volume, non-EU work to Grok 4.5, and verification-critical, long-context, or EU work to GPT-5.5.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
Grok 4.5
Grok 4.5
8.7

A genuine split verdict between two value-tier frontier models that launched on the same day, July 9, 2026, and we will not fake a single overall winner. Grok 4.5 is the raw rate-card and speed play: at $2 per million input tokens and $6 per million output it matches Terra on input and comes in 50 percent below its $12 output, and SpaceXAI markets it as Opus-class and much faster, a vendor claim we do not treat as a benchmarked win. GPT-5.6 Terra is the measured-efficiency, longer-reach model: Artificial Analysis measures its cost per task at about $0.55 against Grok 4.5's $2.49 because it burns far fewer tokens per task, it edges the Intelligence Index 55 to 54 — though on the Coding Agent Index v1.3 Grok 4.5 leads it 64.44 to 55.79 at the same high effort setting, in different harnesses — carries more than double the context at 1,050,000 tokens, ships a fuller native tool stack with a documented February 16, 2026 cutoff, and is available in the EU where Grok 4.5 is blocked under the AI Act's systemic-risk provisions. Neither model has an independently verified SWE-bench Verified score — OpenAI did not submit Terra and Grok 4.5 is too new to appear — so verified coding is a tie by absence, and Grok 4.5 carries a standalone AA-Omniscience reliability caveat with a 54 percent hallucination rate. The pricing itself is split: the rate card favors Grok 4.5 while the independent cost-per-task figure favors Terra, and which governs your bill depends on how token-efficient your workload is. Best for the cheapest raw output rate and speed on non-EU work: Grok 4.5. Best for measured cost per task, long context, marginal capability edges, and EU deployment: GPT-5.6 Terra. No single overall winner — route raw high-volume output outside the EU to Grok 4.5, and reasoning-heavy, long-context, and EU-bound work to GPT-5.6 Terra.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview
9.0

A split verdict between OpenAI's balanced value tier and Google's multimodal flagship, with no single overall winner. Where GPT-5.6 Terra leads: a low $0.55 cost per task on the Artificial Analysis Intelligence Index; a Coding Agent Index v1.3 score of 55.79 through the Codex harness at high reasoning effort, against 30.34 for Gemini 3.1 Pro through the Gemini CLI harness at the same effort; a February 16, 2026 knowledge cutoff against Gemini's January 2025; double the output ceiling at 128,000 tokens against 64,000; a higher long-context threshold, its surcharge starting at 272,000 input tokens against Gemini's 200,000; and general availability since July 9, 2026. Where Gemini 3.1 Pro leads: native multimodal input across text, image, video, audio, and PDF, where Terra takes only text and image; a marginally higher Artificial Analysis Intelligence Index of 57 against 55; a charted LMArena Elo of 1485, where Terra is not charted; and native Google Search and Maps grounding with the deepest first-party distribution of any frontier vendor. On price the two now list identical rates — $2.00 input, $0.20 cached input, and $12.00 output per million tokens, each doubling on input and rising by half on output above its own long-context threshold. Terra is cheaper only between 200,000 and 272,000 tokens, where Gemini has stepped up and Terra has not. Neither model has an independently verified SWE-bench score: Terra was not submitted, and Gemini's 80.6 percent is self-reported on DeepMind's model card, not run by vals.ai. Best for value coding, long output, the freshest knowledge, and prompts between 200,000 and 272,000 tokens: GPT-5.6 Terra. Best for native multimodal input and the Google ecosystem: Gemini 3.1 Pro. Route agentic coding and long-output work to Terra, and multimodal, small-context, and Google-native work to Gemini 3.1 Pro.

Grok 4.5
Grok 4.5
8.7
VS
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview
9.0

A split verdict between SpaceXAI's aggressively priced flagship and Google's multimodal flagship, with no single overall winner. Where Grok 4.5 leads: a flat $6 per million output tokens that is half of Gemini's $12 up to 200,000 tokens and a third of its $18 above that; the independent Artificial Analysis Coding Agent Index v1.3 at 64.4 against 30.3 for Gemini 3.1 Pro; flat pricing with no context-length surcharge; and general availability since July 9, 2026. Where Gemini 3.1 Pro leads: native multimodal input across text, image, video, audio, and PDF, where Grok takes only text and image; a marginally higher Artificial Analysis Intelligence Index of 57 against 54; a charted LMArena Elo of 1485, where Grok is not charted; double the context window at 1,000,000 tokens against 500,000; cheaper cached-input reads at $0.20 per million against Grok's flat $0.50; and availability in the European Union, where Grok 4.5 is not offered under the EU AI Act's systemic-risk designation. Input price is level at the standard band ($2 per million each). Neither model has an independently verified SWE-bench score: Grok 4.5 is too new to appear on vals.ai, and Gemini's 80.6 percent is self-reported on DeepMind's model card. Artificial Analysis also flags a 54 percent hallucination rate for Grok 4.5 on its AA-Omniscience index, a documented reliability caution, and SpaceXAI's 'Opus-class, much faster' framing is a vendor claim pending independent latency benchmarks. Best for cheap output, coding value, and predictable flat billing outside the EU: Grok 4.5. Best for native multimodal input, aggregate intelligence, long context, and EU availability: Gemini 3.1 Pro. Route output-heavy generation and agentic coding to Grok, and multimodal, very-long-context, Google-native, and EU-bound work to Gemini 3.1 Pro.

Claude Fable 5
Claude Fable 5
9.6
VS
GLM-5.2
GLM-5.2
8.5

This is a deliberate split, not a hedge, because Claude Fable 5 and GLM-5.2 are built for different buyers, and we will not crown a single overall winner. Claude Fable 5 is the more capable model and the only one of the two with elite independent verification: it scores 59.9 on the Artificial Analysis Intelligence Index as of August 4, 2026 (second only to Claude Opus 5's 60.7), posts an independent 95 percent on SWE-bench Verified via vals.ai, and holds a top-ten LMArena rating, all for a premium $10 per million input tokens and $50 per million output. GLM-5.2 answers with cost and openness: at $1.40 input and $4.40 output per million tokens it is roughly seven times cheaper on input and eleven times cheaper on output, adds a flat GLM Coding Plan from around $18 per month, ships MIT-licensed open weights you can self-host and fine-tune, and posts a strong Zhipu self-reported SWE-bench Pro of 62.1. Those two headline coding numbers measure different benchmarks under different regimes, Fable's 95 percent independently verified and GLM's 62.1 vendor-reported, so they cannot be stacked as a head-to-head. Best for top-tier independently verified intelligence, coding, and creative writing: Claude Fable 5. Best for price, open weights, self-hosting, and predictable flat billing: GLM-5.2. No single overall winner, pay the closed premium when capability and verification lead your decision, and self-host the open weights when cost and control do.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
GLM-5.2
GLM-5.2
8.5

There is no single winner here, and that is a finding rather than a hedge. GPT-5.6 Terra is measurably the more intelligent model: 55 against GLM-5.2's 51 on the Artificial Analysis Intelligence Index, the one independent yardstick that scores them both, though on that lab's Coding Agent Index v1.3 it is GLM-5.2 that is charted, at 43.18, with Terra absent. GLM-5.2 is dramatically the cheaper model and the only one you can own: $1.40 input and $4.40 output per million tokens against Terra's $2.00 and $12 — a little over a third of the output bill — with MIT-licensed weights you can download, self-host, and fine-tune, and a flat GLM Coding Plan from around $18 per month. The decision reduces to one question: is the model your product, or your cost center? If output quality is what your customers pay for, Terra's four points are cheap and you should stop optimizing the invoice. If the model is infrastructure you run at volume, GLM-5.2 at a little over a third of the output cost, hostable inside your own walls, is the more rational buy — and at 51 on the independent index, the top open-weight score in the world, you are no longer sacrificing much capability to get it. On coding specifically, no verdict is possible: GLM-5.2's 43.18 on the Coding Agent Index v1.3 is independent, its 62.1 on SWE-bench Pro is vendor self-reported, the two measure different things on different scales, and Terra carries neither. Run both on your own repository.

Claude Opus 4.8
Claude Opus 4.8
9.5
VS
GLM-5.2
GLM-5.2
8.5

This is a split decision, and both halves of it are emphatic. Claude Opus 4.8 is the more capable model, and the evidence points one way: 56 against GLM-5.2's 51 on the Artificial Analysis Intelligence Index — the only independent yardstick that scores them both — and 69.2 against 62.1 on SWE-bench Pro, the only coding benchmark both vendors report, though both of those coding figures are vendor self-reported rather than independently reproduced. Two different measures, same direction. GLM-5.2 answers with economics that are just as decisive: $1.40 input and $4.40 output per million tokens against Opus 4.8's $5 and $25, which is about 3.6 times and 5.7 times cheaper, plus MIT-licensed open weights you can self-host and fine-tune, a documented one-million-token context window where Anthropic publishes no figure at all for Opus 4.8, and a flat coding plan from around $18 per month. It gives up roughly 9 percent of measured intelligence to do all of that. The tie-breaker is not a benchmark, it is your cost structure: if the model's output is your product and a failed unattended run costs an engineer a day, five points of intelligence is cheap and you should stop optimizing the invoice. If the model is infrastructure you burn at volume, or if your data cannot leave your network, GLM-5.2 at about a fifth of the output cost, running on hardware you control, is the more rational purchase. Most engineering organizations should route the hard, unattended work to Opus 4.8 and everything else to GLM-5.2. One caveat that applies either way: the coding numbers on both sides are vendor-reported and Opus 4.8's context window is unpublished, so test on your own repository instead of trusting either leaderboard.

Claude Fable 5
Claude Fable 5
9.6
VS
Kimi K2.7 Code
Kimi K2.7 Code
8.4

Claude Fable 5 wins this comparison, narrowly, and on verified evidence rather than on value. It leads the index that measures both: 60 against Kimi K2.7 Code's 42 on the independent Artificial Analysis Intelligence Index v4.1, read on August 2, 2026 — second only to Claude Opus 5 — and it adds 1509 on LMArena and 95 percent on SWE-bench Verified as measured independently by vals.ai, neither of which Kimi has a third-party equivalent for. Kimi K2.7 Code has no independent coding score we have been able to find — its SWE-bench Verified figure of 60.4 percent is self-reported by Moonshot AI and unreplicated, so it cannot be set against Fable 5's verified 95 percent. The eighteen-point intelligence gap is real, but it sits on a generalist composite of nine mostly non-coding evaluations, and Kimi K2.7 Code is a coding-specialized model. That does not make K2.7 a bad model; it makes it an unverifiable one, which is a different and temporary problem. K2.7 wins more rows than Fable 5 here, and wins them decisively: roughly 10.5 times cheaper on input (USD 0.95 against USD 10), roughly 12.5 times cheaper on output (USD 4 against USD 50), open weights under a Modified MIT license, self-hostable, and fully documented architecturally. The rule: if you can evaluate the model yourself on your own tasks, pick K2.7 — your own measurement is worth more than eighteen points on a generalist index, and the price is not close. If you cannot, pick Claude Fable 5, because you are then choosing between a number a third party verified and a number a vendor asserted. If an independent coding result lands for Kimi K2.7 Code and confirms Moonshot's figures, this verdict should be revisited.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
Kimi K2.7 Code
Kimi K2.7 Code
8.4

GPT-5.6 Terra wins this comparison, on an exchange rate rather than a knockout. It is the higher-scoring of the two on the index that measures both: 55 against Kimi K2.7 Code's 42 on the independent Artificial Analysis Intelligence Index v4.1, read on August 2, 2026. On coding, the independent Artificial Analysis Coding Agent Index v1.3 charts GPT-5.6 Terra at 62.28, through the Codex harness at max reasoning effort, and carries no Kimi K2.7 Code entry; nor have we found an independent coding score for Kimi K2.7 Code anywhere else — the coding figures Moonshot AI publishes are self-reported on its own harness, unreplicated, and drawn from a different benchmark family, so they cannot be set against Terra's charted score. The thirteen-point intelligence gap is real, but it sits on a generalist composite of nine mostly non-coding evaluations, and Kimi K2.7 Code is a coding-specialized model. That does not make Kimi K2.7 Code a bad model; it makes it an unverifiable one, which is a different and temporary problem. What tips the verdict is price. Terra costs roughly 2.6 times more on input (USD 2.50 against USD 0.95) and roughly 3.75 times more on output (USD 15 against USD 4), with cached input nearly level at USD 0.25 against USD 0.19 — the smallest premium any independently scored flagship charges over Kimi K2.7 Code, where the frontier tier charges ten to twelve times more. Thirteen index points plus roughly four times the context (1,050,000 tokens against 256,000) for that surcharge is an unusually good deal. Kimi K2.7 Code still wins price on every line, open weights under a Modified MIT license, self-hosting, and architectural transparency. The rule: if you can evaluate the model yourself, or you must self-host, or your volume runs to hundreds of millions of output tokens a month, pick Kimi K2.7 Code. Otherwise pick GPT-5.6 Terra, because the price of proof has rarely been this low. If an independent coding result lands for Kimi K2.7 Code and confirms Moonshot's figures, this verdict should be revisited.

Grok 4.5
Grok 4.5
8.7
VS
Kimi K2.7 Code
Kimi K2.7 Code
8.4

Grok 4.5 wins this comparison, on an exchange rate rather than a knockout — and the win is scoped. It leads the one index that measures both: 54 against Kimi K2.7 Code's 42 on the independent Artificial Analysis Intelligence Index v4.1, read on August 2, 2026, and it adds 64.4 on the independent Artificial Analysis Coding Agent Index v1.3, measured through the Grok Build harness at high effort. Kimi K2.7 Code has no third-party coding score we have been able to find; the coding figures Moonshot AI publishes (SWE-bench Verified 60.4 percent, SWE-bench Pro 58.6) are self-reported on its own harness, unreplicated, and from a different benchmark family, so they cannot be set against Grok's charted numbers. The twelve-point intelligence gap is real, but that index is a generalist composite of nine mostly non-coding evaluations and Kimi K2.7 Code is a coding-specialized model — so it is measured and behind on breadth, not proven weaker at the job it was built for. What settles it is the price of that proof, and it has never been lower: Grok 4.5 costs about 2.1 times more on input (USD 2 against USD 0.95) but only about 1.5 times more on output (USD 6 against USD 4), the line that dominates a real coding bill. For a solo developer that premium is roughly eleven dollars a month, and it buys twelve index points plus close to double the context window (500,000 tokens against 256,000). Two caveats scope the win hard. Grok 4.5 is currently blocked in the European Union under the EU AI Act; SpaceXAI signalled a staged opening around mid-July 2026, so EU readers must verify availability for their region before acting on any of this. And Grok 4.5 carries a measured 54 percent hallucination rate on the independent AA-Omniscience evaluation, which argues for keeping a human or a test suite in the loop on anything requiring the model to know rather than to build. K2.7 remains the right call, without hesitation, if you are in the EU today, if you must self-host or keep data inside your own perimeter, if you burn hundreds of millions of output tokens a month, or if you can evaluate the model yourself and therefore do not need a third party to have done it for you. It is cheaper on every line, open on every axis, and available everywhere. If an independent coding result lands for Kimi K2.7 Code and confirms Moonshot's figures, this verdict should be revisited immediately.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Qwen 3.6
Qwen 3.6
8.5

GPT-5.6 Sol is the narrow overall winner on measured capability, and by the widest independent margin in this series: 59 against 40 on the Artificial Analysis Intelligence Index v4.1, a 19-point gap that places Qwen 3.6 Plus below every model in the GPT-5.6 family, including the cheapest. Sol adds a charted independent AA Coding Agent Index v1.3 score of 66.57, second of 52, and a marginal context edge (1.05M against 1M). But Qwen 3.6 wins the economics decisively: Qwen 3.6 Plus costs $0.325 per million input tokens and $1.95 per million output tokens against Sol's $5.00 and $30.00 — about 15 times cheaper on both ends — and the family ships open weights under Apache 2.0, the most permissive license on the market. The critical catch: the 40-scoring model, Qwen 3.6 Plus, is closed; the open weights belong to smaller, separate models (Qwen3.6-27B and Qwen3.6-35B-A3B), so choosing Qwen for openness means running a different model than the one that posts the intelligence score. Coding evidence is asymmetric and we do not fake symmetry: Sol's AA Coding Agent Index v1.3 score of 66.57 is independent and applies to the exact model in play, while Qwen's SWE-bench Verified figures are vendor self-reported by Alibaba for the open-weight variants, so the two are never placed side by side. The decision reduces to one question, plus a second: is the capability you are buying capability you actually need, and which Qwen would you actually run? If the model's ceiling constrains your work, pay for Sol. If your tasks are well-specified enough that a 19-point gap never binds, or an Apache-2.0 open license is a hard requirement, Qwen 3.6 is the rational default.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
Qwen 3.6
Qwen 3.6
8.5

GPT-5.6 Terra wins this comparison on measured capability, but the value case for Qwen 3.6 Plus is the strongest we have set against a GPT-5.6 tier. Both flagships are scored on the same version of the same independent index by the same evaluator: Terra 55, Qwen 3.6 Plus 40. Fifteen points on a scale whose highest posted score to date is 60 is not a rounding error; it is the difference between the leading group and the capable middle, and it shows up on long unsupervised chains as tasks that finish versus tasks that need you. Terra also holds a marginally larger context window and a marginal edge on context (1,050,000 tokens against 1,000,000). What makes the trade so sharp is the price. Qwen 3.6 Plus is roughly 7.7 times cheaper on both input and output — USD 0.325 against USD 2.50, USD 1.95 against USD 15 — the widest price gap in this series, and it wins measured intelligence per dollar by more than five times, with both sides of that ratio independently sourced. It is also natively multimodal (text, image, video) and belongs to a family with Apache 2.0 open-weight siblings, giving a self-hosting escape hatch Terra cannot match — though the Plus flagship itself is closed, API-only, exactly like Terra. The rule: if budget binds, or your volume runs to hundreds of millions of output tokens a month, or you need multimodal input, pick Qwen 3.6 Plus. Otherwise, if capability bounds your work and you need the only independent coding evidence in the pairing, pick GPT-5.6 Terra. One caution on the data: the independent 40 describes Qwen 3.6 Plus specifically, not the open-weight variants, which have no comparable independent score.

Grok 4.5
Grok 4.5
8.7
VS
Qwen 3.6
Qwen 3.6
8.5

This comparison does not have a single winner, and we are not going to invent one — it is a genuine split. Grok 4.5 owns the measure: on version 4.1 of the independent Artificial Analysis Intelligence Index it scores 54 against Qwen 3.6 Plus's 40, a fourteen-point lead from the same evaluator with neither vendor involved, and it is the only one of the two with an independent coding result at all. If the thing you are buying is how good the model is at thinking, and you can access it, Grok 4.5 is the pick. Qwen 3.6 owns almost everything else: Qwen 3.6 Plus is about six times cheaper on input and about three times cheaper on output, carries a 1,000,000-token context window against Grok's 500,000, and accepts image and video as well as text, while its open-weight Apache 2.0 siblings let you self-host and keep data inside your own perimeter — and both the Plus API and the open weights are available in the European Union, where Grok 4.5 currently is not. For the large majority of teams that are cost-bound, context-bound, in the EU, or need open weights, Qwen 3.6 is the correct answer. Two caveats scope both sides: Grok 4.5 is blocked in the EU today with a staged opening signaled for around mid-July 2026, so verify your region before acting; and Grok 4.5 carries a measured 54 percent hallucination rate on AA-Omniscience, a failure rate on a different axis entirely from its Intelligence Index. On coding we deliberately declare no winner, because Grok's figure is independently charted while Qwen's only coding numbers are self-reported by Alibaba for its open-weight models, a different benchmark family that cannot honestly be set against the independent index.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
MiniMax M3
MiniMax M3
8.6

There is no single winner here, and the split is the finding. GPT-5.6 Terra and MiniMax M3 are both scored on the same version of the same independent index — Terra 55, MiniMax 44 — so the eleven-point capability gap is real and externally measured, not either vendor's claim. Terra also carries a slightly larger 1,050,000-token context, and for quality-bound work that advantage earns its price; on the independent AA Coding Agent Index v1.3 Terra is charted at 62.28 through the Codex harness at max reasoning effort while MiniMax M3 has no entry, so that axis yields evidence on one side rather than a head-to-head. But the price gap is a chasm: MiniMax M3 is roughly 8.3 times cheaper on input and 12.5 times cheaper on output at standard rates, wins measured intelligence per dollar by about tenfold, and adds open weights, self-hosting, data residency, and native multimodality across text, image, and video — things a hosted API cannot offer at any price. Its one honest asterisk, rates that double above 512,000 tokens, still leaves it several times cheaper than Terra even at extreme context. The rule: if quality is your binding constraint — long unsupervised agents, unedited customer output, reasoning-heavy work — pick GPT-5.6 Terra. If cost, control, or modality is your binding constraint — high volume, self-hosting, compliance, or native image and video — pick MiniMax M3. Both are correct answers to different questions; the only wrong move is choosing on the price sticker or the benchmark alone without asking which constraint your own workload is actually bound by.

Grok 4.5
Grok 4.5
8.7
VS
MiniMax M3
MiniMax M3
8.6

Grok 4.5 versus MiniMax M3 is a genuine value split, and we record it as one rather than forcing a winner. Grok 4.5 wins measured intelligence — 54 to 44 on the same independent Artificial Analysis Intelligence Index (version 4.1) — and it is the only model of the two with an independently charted coding score, so it owns the single axis where the capability evidence comes from outside the vendor. MiniMax M3 wins nearly everything else on the spec sheet: output that costs five times less at USD 1.20 against USD 6 per million tokens, twice the context at one million tokens, an open-weight mixture-of-experts design you can eventually self-host, published architecture, and native multimodality. That MiniMax M3 wins more rows does not settle the decision, because its advantages rest heavily on vendor-reported numbers and weights that had not shipped at the time of writing, while Grok 4.5's rest on independent measurement. Two caveats scope each side. Grok 4.5 is restricted in the European Union as of mid-July 2026 under the EU AI Act — SpaceXAI has signalled a staged opening, so this is today's state rather than a permanent one, and EU readers must verify access for their region before building. And Grok 4.5 carries a measured 54 percent hallucination rate on the independent AA-Omniscience evaluation, a failure rate on a different axis from its Intelligence Index, which argues for retrieval or human review on factual work. MiniMax M3's caveats are the verification gap and jurisdiction: until its weights ship, its capability numbers are the vendor's own and the only way to run it is a hosted API operated from China, under Chinese data law. The decision reduces to one question — do you value capability a third party has proven, at a premium, or price, context, and control on vendor faith? Buyers who need independently proven capability should pick Grok 4.5; buyers who optimize for cost, context length, and openness should pick MiniMax M3. There is no universal winner here, only the right tool for the axis that binds your work.

Claude Fable 5
Claude Fable 5
9.6
VS
MiniMax M3
MiniMax M3
8.6

Claude Fable 5 versus MiniMax M3 is the widest capability-versus-cost spread we have tested — the sharpest fork in this comparison series. Claude Fable 5 is the most capable model in our coverage: it scores 60 on the independent Artificial Analysis Intelligence Index at version 4.1 against 44 for MiniMax M3 on the same index and the same version, a 16-point lead and the highest figure across every model we track. In our own production testing it held state deeper into long agent runs and reached correct results with fewer human interventions on the hardest multi-file migrations, backed by the deepest agent toolkit and the most mature production safety design in this matchup — refusals return a clean success response with an automatic fallback to Claude Opus 4.8, and refused-before-output requests are not billed. MiniMax M3 wins everything economic and open: its standard output price of 1.20 dollars per million tokens is about 42 times cheaper than Fable 5's 50 dollars, its input at 0.30 dollars is about 33 times cheaper than Fable 5's 10 dollars, the model ships open-weight for self-hosting, and it is natively multimodal across text, image, and video. Two nuances scope MiniMax's cost story: its rate doubles above 512K tokens, so filling the shared one-million-token window is not billed at the headline price, and its hosted API is operated by a Chinese company under China's data laws, though open weights make self-hosting the escape hatch. There is no single overall winner, and pretending otherwise would fail the reader. If you are capability-bound and the cost of being wrong dwarfs the token bill, Claude Fable 5 earns its premium. If you are cost-bound and running at scale, MiniMax M3 delivers a remarkable share of frontier quality for a fraction of the price. The 42-times output price gap and the 16-point independent intelligence gap point in opposite directions, and your workload decides.

Claude Opus 4.8
Claude Opus 4.8
9.5
VS
MiniMax M3
MiniMax M3
8.6

Claude Opus 4.8 versus MiniMax M3 is a clean capability-versus-cost fork with no single overall winner. Claude Opus 4.8 is the more capable model on the neutral scale: it scores 56 on the independent Artificial Analysis Intelligence Index at version 4.1 against 44 for MiniMax M3 on the same index and version, a 12-point lead by a neutral evaluator, and it pairs that with the deeper agent ecosystem in this matchup — Dynamic Workflows for parallel subagents, effort controls, and a cautious self-checking reliability personality that held instructions tightly and needed fewer human interventions on the hardest work in our production testing. MiniMax M3 wins everything economic and open: its standard output price of 1.20 dollars per million tokens is about 21 times cheaper than Opus 4.8's 25 dollars, its input at 0.30 dollars is about 17 times cheaper than Opus 4.8's 5 dollars, it ships open-weight for self-hosting, and it is natively multimodal across text, image, and video. Two nuances scope MiniMax's cost story: its rate doubles above 512K tokens, so filling the shared one-million-token window is not billed at the headline price, and its hosted API is operated by a Chinese company under China's data laws, though open weights make self-hosting the escape hatch. Pick Claude Opus 4.8 when the cost of being wrong dwarfs the token bill and you want a deep managed ecosystem; pick MiniMax M3 when the token bill is the whole constraint and you can run at scale. The 21-times output price gap and the 12-point independent intelligence gap point in opposite directions, and your workload decides.

Claude Sonnet 5
Claude Sonnet 5
9.3
VS
MiniMax M3
MiniMax M3
8.6

There is no single winner here, and the split is the finding. Claude Sonnet 5 and MiniMax M3 are both scored on the same version of the same independent index — Sonnet 53, MiniMax 44 — so the nine-point capability gap is real and externally measured, not either vendor's claim. Sonnet 5 also carries a managed Anthropic ecosystem and prices its 1,000,000-token context flat, and for quality-bound work those advantages earn their price. But the price gap, though narrower than the ones MiniMax opens against pricier flagships, still runs every way: MiniMax M3 is roughly 6.7 times cheaper on input and 8.3 times cheaper on output — wins measured intelligence per dollar by about sevenfold, and adds open weights, self-hosting, data residency, and native multimodality that a hosted API cannot offer at any price. Its one honest asterisk, rates that double above 512,000 tokens, still leaves it several times cheaper than Sonnet even at extreme context. The rule: if quality is your binding constraint — long unsupervised agents, unedited customer output, reasoning-heavy work — pick Claude Sonnet 5. If cost, control, or modality is your binding constraint — high volume, self-hosting, compliance, or native image and video — pick MiniMax M3. Both are correct answers to different questions; the only wrong move is choosing on the price sticker or the benchmark alone without asking which constraint your own workload is actually bound by.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Kimi K3
Kimi K3
8.7

This is a genuine split, and the tightest Sol has faced from an open challenger: GPT-5.6 Sol keeps a narrow lead on measured capability while Kimi K3 answers with a decisive price cut and an open-weight promise. On the independent Artificial Analysis Intelligence Index version 4.1, Sol scores 59 to Kimi K3's 57 — a two-point gap on the same harness, down from the seventeen points Sol held over the older Kimi K2.7 Code. Sol also leads the independent agentic-coding index, 66.57 against 61.34 on the Coding Agent Index v1.3, and a marginally larger 1,050,000-token context against Kimi K3's 1,000,000. Kimi K3 wins the economics: $3 input and $15 output per million tokens against Sol's $5 and $30 — 40 percent cheaper on input and exactly half the price on output — plus a roughly 2.8-trillion-parameter Mixture-of-Experts architecture with about 50 billion active parameters, Kimi Delta Attention, native vision, and open weights promised under a Modified MIT license. The critical caveat: those weights are not public yet, and Moonshot targets July 27, 2026, so today Kimi K3 is open-weight-in-waiting rather than downloadable. Moonshot's other headline numbers are self-reported in its own harness and never placed beside Sol's independent scores. We do not crown one winner because the evidence honestly splits: pick GPT-5.6 Sol for the hardest reasoning, the largest context, and a proven independent coding record; pick Kimi K3 for output cost, architectural efficiency, and open weights you can plan around.

Claude Fable 5
Claude Fable 5
9.6
VS
Kimi K3
Kimi K3
8.7

There is no overall winner here, and that is a conclusion rather than a hedge: Claude Fable 5 and Kimi K3 answer different questions. On the same version 4.1 of the independent Artificial Analysis Intelligence Index, read mid-July 2026, Claude Fable 5 scored 60 — then the highest figure any model had recorded — while Kimi K3 scored 57, third overall at that reading and above Claude Opus 4.8 at 56. Claude Opus 5, charted July 24, 2026, now leads at 60.7, with Fable 5 at 59.9 and Kimi K3 at 57.1 as of August 4, 2026. That three-point gap is the narrowest an open-weight model has come to the closed summit, and it is independently measured rather than asserted. Against it, Kimi K3 charges USD 3 per million input tokens and USD 15 per million output tokens against Claude Fable 5’s USD 10 and USD 50 — roughly 3.3 times cheaper both ways — matches Fable’s 1,000,000-token context window, discloses its mixture-of-experts architecture, and is licensed as open-weight with the weights promised for July 27, 2026. Kimi K3’s coding and agentic benchmarks are Moonshot-reported and not yet independently replicated, so they are never set against Fable 5’s figures on this page. The rule that settles it: if the hardest task in your workload sits above what a 57-index model can finish, buy Claude Fable 5, because those extra points of measured ceiling are the whole reason it exists. If it sits below that line, and for most teams it does, buy Kimi K3, which delivers near-frontier intelligence, the same context window, and openness in waiting for about a third of the cost. Best for measured intelligence and a verified ceiling: Claude Fable 5. Best for price, openness, and value at near-frontier quality: Kimi K3.

Claude Fable 5
Claude Fable 5
9.6
VS
Kimi K2.6
Kimi K2.6
8.5

There is no overall winner here, and that is a conclusion rather than a hedge: Claude Fable 5 and Kimi K2.6 are not substitutes for one another. Both models are scored on the same version 4.1 of the independent Artificial Analysis Intelligence Index, which makes the trade unusually clean — Claude Fable 5 posts 60, the highest score any model has recorded, while Kimi K2.6 posts 44. That is a real, third-party-measured gap of 16 points. Against it stands a price gap that runs the other way and runs harder: Claude Fable 5 charges USD 10 per million input tokens, USD 1 cached, and USD 50 per million output tokens, while Kimi K2.6 charges USD 0.95, USD 0.16, and USD 4 — roughly 10.5 times cheaper on input and 12.5 times cheaper on output, with open weights under a Modified MIT license, self-hosting, a published ceiling of 300 sub-agents across 4,000 coordinated steps, and a fully disclosed mixture-of-experts architecture. On coding, the evidence is asymmetric and cannot be stacked: Claude Fable 5's 95 percent on SWE-bench Verified was measured independently by vals.ai, whereas Kimi K2.6's 58.6 on SWE-bench Pro is a different benchmark measured by Moonshot AI itself, so the two figures are never set against each other on this page. The rule that settles it: if the hardest task in your workload sits above what a 44-index model can complete, buy Claude Fable 5 — Kimi K2.6 will not finish the job at any price and the premium is irrelevant. If it sits below that line, and for most teams it does, buy Kimi K2.6 — Claude Fable 5 is then charging roughly eleven times more for a ceiling you will never reach. Best for measured intelligence, verified coding evidence, and 1M-token context: Claude Fable 5. Best for price, open weights, data residency, and high-volume agentic loops: Kimi K2.6.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
Kimi K2.6
Kimi K2.6
8.5

GPT-5.6 Terra wins this comparison, and it is the narrowest call in this family — because for once the open model came with receipts. Both models are scored on the same version of the same independent index by the same evaluator: Terra 55, Kimi K2.6 44. Eleven points on a scale whose highest posted score to date is 60 is not a rounding error; it is the difference between the leading group and the head of the tier below, and it shows up on long unsupervised chains as tasks that finish versus tasks that need you. Terra also carries roughly four times the context (1,050,000 tokens against 256,000). Both models are charted on the independent AA Coding Agent Index v1.3, but through different harnesses: Terra 62.28 through Codex at max reasoning effort, Kimi K2.6 32.62 through Claude Code — so Terra takes that axis too, with the harness gap stated rather than hidden. What makes the verdict close is the price. Kimi K2.6 is cheaper on every line — USD 0.95 against USD 2.50 on input, USD 0.16 against USD 0.25 cached, USD 4 against USD 15 on output — and it wins measured intelligence per dollar by roughly a factor of three, with both sides of that ratio independently sourced. It also wins open weights under a Modified MIT license, self-hosting, full architectural disclosure, and a published agent orchestration ceiling of up to 300 subagents across as many as 4,000 steps. GPT-5.6 Terra is simply the closest an independently scored closed model gets to Kimi K2.6 on price — roughly 2.6 times on input where the frontier tier charges eight to twelve times more — which makes eleven measured points plus four times the context an unusually good buy. The rule: if budget is your binding constraint, or you must self-host, or your volume runs to hundreds of millions of output tokens a month, pick Kimi K2.6. Otherwise pick GPT-5.6 Terra. One caution on the data: Kimi K2.6's index score is 44, not the 54 widely quoted, which comes from a previous version of the index and is not comparable to current-version scores.

Grok 4.5
Grok 4.5
8.7
VS
Kimi K2.6
Kimi K2.6
8.5

Grok 4.5 wins this comparison, and unusually for a closed-versus-open matchup it wins on measurement rather than on faith. Both models have been scored by the same independent evaluator on the same yardstick — version 4.1 of the Artificial Analysis Intelligence Index — and Grok 4.5 takes 54 against Kimi K2.6's 44. Ten points, no vendor involved. (The 54 widely circulated for Kimi K2.6 comes from an earlier version of that index and is stale; on the current version it is 44, and we never use the old figure as a score.) Add close to double the context window, 500,000 tokens against 256,000, and Grok 4.5 leads on the two things hardest to work around. What settles it is the price of those ten points, and it has never been lower: Grok 4.5 costs about 2.1 times more on input (USD 2 against USD 0.95) but only about 1.5 times more on output (USD 6 against USD 4), the line that dominates a real coding bill. For a solo developer that premium is roughly eleven dollars a month. Two caveats scope the win hard. Grok 4.5 is currently blocked in the European Union under the EU AI Act; SpaceXAI signalled a staged opening around mid-July 2026, so EU readers must verify availability for their region before acting on any of this — it is the fastest-moving fact on the page. And Grok 4.5 carries a measured 54 percent hallucination rate on the independent AA-Omniscience evaluation, a failure rate on a different axis entirely from its Intelligence Index, which argues for keeping a human or a test suite in the loop on anything requiring the model to know rather than to build. On coding, we deliberately declare no winner: Grok 4.5's coding figure is independently charted, Kimi K2.6's is self-reported by Moonshot AI on its own harness and belongs to a different benchmark family, so the two cannot honestly be set against each other. Kimi K2.6 remains the right call, without hesitation, if you are in the EU today, if you must self-host or keep data inside your own perimeter, if you burn hundreds of millions of output tokens a month, or if your workload decomposes into the massively parallel agent swarm Grok has no answer to. It is cheaper on every line, open on every axis, available everywhere, and — unlike most of the open-weight field — genuinely measured by somebody other than the company selling it.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Claude Sonnet 5
Claude Sonnet 5
9.3

A split verdict between OpenAI's flagship and Anthropic's balanced value tier, and we will not fake a single overall winner. GPT-5.6 Sol is the capability leader: on the independent Artificial Analysis Intelligence Index it scores 59 against Claude Sonnet 5's 53, it places second at 66.57 on the Coding Agent Index v1.3 where Sonnet 5 is not charted, it adds an ultra multi-agent reasoning mode Sonnet 5 has no equivalent to, a marginally larger 1,050,000-token context against 1,000,000, a newer February 16, 2026 knowledge cutoff versus January 2026, and it is the only one of the two charted on LMArena at 1486 (No.8). Claude Sonnet 5 is the price, speed, and reach leader: its $2 per million input tokens and $10 per million output undercut Sol's $5 and $30 by roughly 60 to 67 percent; Artificial Analysis measures it faster at 79 output tokens per second against Sol's 74.5; it is the default model on the free and Pro plans of Claude.ai; and it reaches a 300,000-token output ceiling via a Batch beta. One honest caveat sits on the price story: Anthropic states Sonnet 5's newer tokenizer counts roughly 30 percent more tokens for the same text, which narrows the effective discount. Neither model has been submitted to independent SWE-bench Verified. Best for peak capability, agentic coding, and the deepest reasoning: GPT-5.6 Sol. Best for the lowest price, measured speed, and the widest free reach: Claude Sonnet 5. No single overall winner — the real question is not which is better but whether your workload needs the flagship, and for many teams the balanced Claude is already enough.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Kimi K2.6
Kimi K2.6
8.5

GPT-5.6 Sol is the winner on measured capability, and by the widest independent margin in this series: 59 against 44 on the Artificial Analysis Intelligence Index v4.1, a 15-point gap that places Kimi K2.6 below every model in the GPT-5.6 family, including the cheapest. Sol adds a charted independent AA Coding Agent Index v1.3 score of 66.57, second of 52, and roughly four times the context window (1.05M against 256K). But Kimi K2.6 wins the economics decisively: $0.95 per million input tokens and $4.00 per million output tokens against Sol’s $5.00 and $30.00 — about five times cheaper on input and exactly seven and a half times cheaper on output — on a model whose open weights you can self-host and fine-tune under a Modified MIT license. On the independent Coding Agent Index v1.3 both are charted, but through different harnesses — Sol 66.57 through Codex at max effort, Kimi K2.6 32.62 through Claude Code — and we state the harness rather than presenting the 33.95-point gap as if one agent had run both. What stays asymmetric is Moonshot AI's own SWE-bench Pro 58.6, a vendor self-reported figure we never place beside an independent one. The decision reduces to one question: is the capability you are buying capability you actually need? If the model’s ceiling constrains your work, pay for Sol. If your tasks are well-specified enough that a 15-point index gap never binds, the 7.5-times output premium is headroom you will never touch, and Kimi K2.6 is the rational default.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
GLM-5.2
GLM-5.2
8.5

A clean split between a premium closed flagship and an open-weight value challenger, and we will not invent a single overall winner. GPT-5.6 Sol leads the one independent board that scores both — Artificial Analysis charts it second of ten on its Coding Agent Index v1.3 at 66.57 against GLM-5.2's 43.18 in seventh, and scores it 59 on its Intelligence Index — and it adds an ultra multi-agent reasoning tier, Programmatic Tool Calling, a marginally larger 1,050,000-token context, and a US-hosted stack. GLM-5.2 answers with price and openness: $1.40 per million input tokens and $4.40 per million output tokens against Sol's $5.00 and $30.00, roughly a seventh of the cost on output, plus a flat GLM Coding Plan from around $18 per month and MIT-licensed weights you can self-host and fine-tune. Every GLM-5.2 benchmark is Zhipu self-reported and not yet independently verified, and its production API is hosted in China; the two benchmarks both vendors publish, SWE-bench Pro at 64.6% for Sol against 62.1% for GLM-5.2 and Terminal-Bench 2.1 at 88.8% against 81.0%, are self-reported on each side and measured separately, too close and too differently run to break the tie. Best for independently validated capability, advanced reasoning, and US hosting: GPT-5.6 Sol. Best for price, open weights, and self-hosting freedom: GLM-5.2. No single overall winner — route verifiable, orchestration-heavy, compliance-bound work to GPT-5.6 Sol, and cost-sensitive, self-hosted, or fine-tuning work to GLM-5.2.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
GPT-5.6 Terra
GPT-5.6 Terra
8.7

A true split verdict, capability against value, inside one model family. GPT-5.6 Sol and GPT-5.6 Terra share the same 1,050,000-token context window, the same February 16, 2026 knowledge cutoff, the same 128,000-token output ceiling, and the same Programmatic Tool Calling toolbox — so this is not a fight over features, it is a fight over how much capability you need and how much you want to pay for it. On the independent Artificial Analysis leaderboards, Sol leads: 59 to 55 on the Intelligence Index, and 66.57 to 62.28 on the Coding Agent Index v1.3, both through the Codex harness at max reasoning effort, read August 2, 2026 — the one board where the two tiers can be compared like for like, and the gap there is 4.29 points. Sol alone gets the new ultra multi-agent reasoning mode. Terra answers on price: after OpenAI's July 30, 2026 cut it costs $2.00 input and $12.00 output per million tokens — 40 percent of Sol's rate on both sides — for a model OpenAI positions as GPT-5.5-competitive. Artificial Analysis measured about $0.55 per task for Terra against about $1.04 for Sol before that cut, so Terra's real-world cost advantage is now wider than those figures show. Best for the hardest coding, long-horizon agents, and workloads where the four-point intelligence gap changes outcomes: GPT-5.6 Sol. Best for high-volume business work at a tight budget, where the gap is marginal and the price is not: GPT-5.6 Terra. No single overall winner — pick Sol for the ceiling, Terra for the bill.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview
9.0

A genuine split verdict between two flagships that human voters can barely tell apart. On LMArena, the one independent leaderboard that scores both under identical conditions, GPT-5.6 Sol sits at 1486 Elo and Gemini 3.1 Pro at 1485 — a single point, deep inside the statistical noise. Beyond that dead heat the two vendors publish different benchmarks, so we compare only where the ground is solid and flag every gap. Where GPT-5.6 Sol leads: it places second of ten on Artificial Analysis's Coding Agent Index v1.3 at 66.57, where Gemini 3.1 Pro sits last at 30.34; it carries a marginally larger 1,050,000-token context, double the output ceiling at 128,000 tokens against 64,000, a February 2026 knowledge cutoff against Gemini's January 2025, an ultra multi-agent reasoning mode, and general availability as of July 9, 2026. Where Gemini 3.1 Pro leads: price, decisively — $2 against $5 per million input tokens and $12 against $30 output at the standard tier, both vendor-verified at the source; native multimodal input across text, image, video, audio, and PDF where Sol takes only text and image; native Google Search and Maps grounding; and the deepest first-party distribution of any frontier vendor. On broad intelligence the two are inside the noise — Artificial Analysis Intelligence Index 59 for Sol against 57 for Gemini, measured on different index snapshots. Neither model has an independently verified SWE-bench score: Sol has not been submitted, and Gemini's 80.6 percent is self-reported on DeepMind's model card. Best for the independent coding-agent leaderboard, longest output, newest knowledge, and GA stability: GPT-5.6 Sol. Best for price, native video and audio input, and the Google ecosystem: Gemini 3.1 Pro. No single overall winner — route capability-benchmark-critical agentic coding and long-output work to GPT-5.6 Sol, and cost-sensitive, multimodal, and Google-native work to Gemini 3.1 Pro.

GPT-5.6 Terra
GPT-5.6 Terra
8.7
VS
Claude Sonnet 5
Claude Sonnet 5
9.3

A split verdict between two balanced mid-tier models built for the same job — high-volume production work at a good capability-to-cost ratio — and we will not fake a single overall winner. On the one independent aggregate both appear on, GPT-5.6 Terra edges ahead: Artificial Analysis scores it 55 on the Intelligence Index against Claude Sonnet 5's 53, a two-point gap that sits inside benchmark noise. Neither model is charted on the independent Coding Agent Index v1.3. Terra carries the only published per-task cost figure (about $0.55 to run the Intelligence Index), a marginally larger 1,050,000-token context against Sonnet 5's 1,000,000, and a newer February 16, 2026 knowledge cutoff versus January 2026. Sonnet 5 answers on price and reach: its rate of $2 per million input tokens and $10 per million output matches Terra's $2.00 input and undercuts its $12 output, it is the default model on the free and Pro plans of Claude.ai where Terra is API-, Codex-, and Work-tier only, and Artificial Analysis measures it at 79 output tokens per second where it publishes no Terra figure. One honest caveat levels the price story: Anthropic notes Sonnet 5's newer tokenizer counts roughly 30 percent more tokens for the same text, which narrows the effective-cost gap. Neither model has been submitted to independent SWE-bench Verified. Best for the independent intelligence and coding indices, per-task economics, longest context, and newest knowledge: GPT-5.6 Terra. Best for the lowest price and the widest consumer reach: Claude Sonnet 5. No single overall winner — route capability-benchmark-sensitive and long-context work to Terra, and price-sensitive or consumer-facing work to Sonnet 5, and test both on your own prompts before committing.

Grok 4.5
Grok 4.5
8.7
VS
Claude Opus 4.8
Claude Opus 4.8
9.5

A split verdict, and we will not fake a single overall winner. Elon Musk positions Grok 4.5 as "Opus-class, much faster" at less than half the price, and on the independent Artificial Analysis Coding Agent Index v1.3 the claim has partial support: Grok 4.5 scores 64.4 through Grok Build at less than half the token price, against 56.70 for Claude Opus 4.8 through Claude Code at the same high effort. But "Opus-class" is not yet independently confirmed against Opus 4.8 on verified coding: Grok 4.5 is only two days old and does not yet appear on vals.ai's independent SWE-bench Verified leaderboard, where Claude Opus 4.8 is verified at 88.6 percent — so the independently verified coding edge is Opus 4.8's. Grok 4.5 is also dramatically cheaper, at $2 per million input tokens and $6 per million output against Opus 4.8's $5 and $25, both vendor-verified, and Artificial Analysis measures its cost per task at about $2.49 on its Intelligence Index run, low in the frontier tier. The "Opus-class" label does not extend across the board. On the Artificial Analysis Intelligence Index, Grok 4.5 scores 54 and ranks fourth in the frontier field, while Opus 4.8 reads between 56 and 61 depending on configuration — higher at both ends. On reliability, Artificial Analysis's AA-Omniscience test flags a 54 percent hallucination rate for Grok 4.5, and Opus 4.8 carries a 1,000,000-token context window to Grok's 500,000. One hard practical fact sits outside the benchmarks: Grok 4.5 is not available in the EU under the AI Act, while Opus 4.8 is. Best for the lowest token price, coding value per dollar, and vendor-stated speed on non-EU work: Grok 4.5. Best for independently verified coding, measured intelligence, reliability, long context, and EU availability: Claude Opus 4.8. "Opus-class" is credible on coding value and price, but unconfirmed on independently verified coding and unproven on general intelligence and reliability — so route accordingly rather than crown one model.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Claude Opus 4.8
Claude Opus 4.8
9.5

A split verdict between two frontier flagships, and we will not fake a single overall winner. GPT-5.6 Sol and Claude Opus 4.8 charge the same $5 per million input tokens; Opus 4.8 is cheaper on output at $25 against $30 per million. On independent leaderboards the two split cleanly: Artificial Analysis charts GPT-5.6 Sol second of 52 on its Coding Agent Index v1.3 at 66.57, against 60.54 for Opus 4.8 at the same max effort in the Claude Code harness, while Claude Opus 4.8 posts an independently verified 88.6 percent on the vals.ai SWE-bench Verified suite, a leaderboard GPT-5.6 Sol has not been submitted to. Sol carries a marginally larger 1,050,000-token context and a February 2026 knowledge cutoff, and is measured cheaper per task at about $1.04 on Artificial Analysis's Intelligence Index run. Opus 4.8 carries cheaper output tokens, the stronger documented computer-use record, and the longer public track record. On broad intelligence the two are inside the noise — Intelligence Index 59 for Sol against a configuration-dependent 56 to 61.4 for Opus 4.8 — and on LMArena human preference they sit at 1486 to 1482. Best for the independent coding-agent leaderboard, longest context, newest knowledge, and per-task economics: GPT-5.6 Sol. Best for independently verified SWE-bench, cheaper output tokens, and computer-use maturity: Claude Opus 4.8. No single overall winner — route capability-benchmark-critical agentic-coding and long-context work to GPT-5.6 Sol, and independently verifiable, output-heavy, or browser-agent work to Claude Opus 4.8.

GPT-5.6 Sol
GPT-5.6 Sol
8.8
VS
Claude Fable 5
Claude Fable 5
9.6

A genuine split verdict, capability against value. On the independent leaderboards where both models appear, Claude Fable 5 is the measured capability leader of this pair: at the review's mid-July 2026 reading, Artificial Analysis ranked it No.1 on the Intelligence Index at 60 (one point above Sol's 59) and it held the No.1 LMArena Elo at 1509 against Sol's 1486 at No.8 — both No.1 spots have since passed to Claude Opus 5, with Fable 5 at 59.9 to Sol's 58.9 on the index as of August 4, 2026 — and on the independently run SWE-bench Verified suite it posts 95 percent while GPT-5.6 Sol has not been submitted at all. GPT-5.6 Sol answers on economics and agentic throughput: it costs half of Fable 5 at the sticker ($5 versus $10 input, $30 versus $50 output per million tokens, both vendor-verified), Artificial Analysis measures its cost to run the Intelligence Index at $1.86 per task versus $3.15 for Fable 5 (measured August 2, 2026), it ranks second on the AA Coding Agent Index v1.3 at 66.57 against Fable 5's 65.85 (Claude Code with Opus 5 leads at 66.74), and it adds an ultra multi-agent reasoning mode Fable 5 does not offer. Best for peak measured intelligence, human preference, and independently verified coding: Claude Fable 5. Best for price, cost per task, agentic-coding-index throughput, and multi-agent workloads: GPT-5.6 Sol. No single overall winner — route frontier reasoning to Fable 5 and high-volume agentic work to Sol.