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Comparison · 2 models · Updated Oct 4, 2026

Claude Opus 4.6 vs GPT-5.1

Too close to call on our weighted score (Claude Opus 4.6 61, GPT-5.1 60). The right pick depends on what you value most.

  1. Anthropic

    Claude Opus 4.6

    Released Feb 5, 2026

    61/100
    • ECI155.3
    • Price$5.00 / $25.00
    • Context1M
    Full specs Remove Claude Opus 4.6

  2. OpenAI

    GPT-5.1

    Released Nov 13, 2025

    60/100
    • ECI149.7
    • Price$1.25 / $10.00
    • Context400K
    Full specs Remove GPT-5.1

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Too close to call

It is close. Our weighted score puts them within 1 points (Claude Opus 4.6 61/100, GPT-5.1 60/100), so choose by what matters most for your work: Claude Opus 4.6 for raw capability and GPT-5.1 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Opus 4.6Capabilities Index (ECI): Claude Opus 4.6 155.3 · GPT-5.1 149.7
  • Lowest priceGPT-5.1GPT-5.1 $3.44 · Claude Opus 4.6 $10.00 per 1M tokens (3:1 blend)
  • Longest contextClaude Opus 4.6Claude Opus 4.6 1,000,000 · GPT-5.1 400,000 tokens
  • Widest inputsClaude Opus 4.6Claude Opus 4.6: Text, Images, PDFs · GPT-5.1: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightClaude Opus 4.6GPT-5.1
CapabilityCapabilities Index (ECI)50%8578
Price25%224
Inputs & features15%8070
Context window10%6044
Overall100%61/10060/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Claude Opus 4.6 vs GPT-5.1 specifications side by side
SpecificationClaude Opus 4.6AnthropicGPT-5.1OpenAI
Capability
Capabilities Index (ECI)155.3 (best)149.7
ECI rank#27 of 148 (best)#52 of 148
GPQA DiamondGraduate-level science questions90.5% (best)87.6%
FrontierMath Tiers 1–3Research-level mathematics66.0%—
OTIS Mock AIME 2024–2025Competition mathematics94.4% (best)88.6%
SWE-bench VerifiedFixing real GitHub issues78.7% (best)68.0%
SimpleQA VerifiedShort factual questions47.0%48.0% (best)
Price per million tokens
Input$5.00$1.25 (best)
Output$25.00$10.00 (best)
Cached input$0.50$0.125 (best)
Blended (3:1)$10.00$3.44 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial OpenAI API
Limits
Context window1,000,000 tokens (best)400,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · maxYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDclaude-opus-4-6gpt-5.1
API providers33 (best)21
ReleasedFeb 5, 2026Nov 13, 2025
Knowledge cutoffMay 31, 2025Sep 30, 2024
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Claude Opus 4.6$100.00
  • GPT-5.1$32.50
04 — Questions

Which should you choose?

Which is better: Claude Opus 4.6 or GPT-5.1?

It is close. Our weighted score puts them within 1 points (Claude Opus 4.6 61/100, GPT-5.1 60/100), so choose by what matters most for your work: Claude Opus 4.6 for raw capability and GPT-5.1 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Opus 4.6 or GPT-5.1?

GPT-5.1 is cheaper at $1.25 input / $10.00 output per million tokens (official OpenAI API price). Claude Opus 4.6 costs $5.00 input / $25.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for GPT-5.1 versus $10.00 for Claude Opus 4.6 (2.9× as much).

Which scores higher on benchmarks?

Claude Opus 4.6 scores higher on the Capabilities Index (ECI): Claude Opus 4.6 155.3 (#27 of 148) and GPT-5.1 149.7 (#52 of 148). Their confidence ranges do not overlap (153.4–157.3 vs 148.3–151.1), so the gap is a real one. On individual benchmarks: GPQA Diamond — Claude Opus 4.6 90.5%, GPT-5.1 87.6%; OTIS Mock AIME 2024–2025 — Claude Opus 4.6 94.4%, GPT-5.1 88.6%; SWE-bench Verified — Claude Opus 4.6 78.7%, GPT-5.1 68.0%; SimpleQA Verified — GPT-5.1 48.0%, Claude Opus 4.6 47.0%.

Which is better for coding?

Claude Opus 4.6 resolves more real GitHub issues on SWE-bench Verified: Claude Opus 4.6 78.7% and GPT-5.1 68.0%. Both support tool calling for agent workflows.

Which has the bigger context window?

Claude Opus 4.6 has the largest context window at 1,000,000 tokens, against 400,000 for GPT-5.1. Maximum output per response: Claude Opus 4.6 up to 128,000, GPT-5.1 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Claude Opus 4.6 accepts text, images and PDFs; GPT-5.1 accepts text and images. Claude Opus 4.6 handles the widest range of inputs.

Are any of these open source?

No. Claude Opus 4.6 and GPT-5.1 are proprietary and only available through APIs and apps.

Which is newer?

Claude Opus 4.6 is the newest, released Feb 5, 2026. GPT-5.1 came out Nov 13, 2025. Knowledge cutoff: Claude Opus 4.6 May 31, 2025, GPT-5.1 Sep 30, 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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