ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GPT-5 vs GPT-5.1

Too close to call on our weighted score (GPT-5 60, GPT-5.1 60). The right pick depends on what you value most.

  1. OpenAI

    GPT-5

    Released Aug 7, 2025

    60/100
    • ECI150.0
    • Price$1.25 / $10.00
    • Context400K
    Full specs Remove GPT-5

  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 a point (GPT-5 60/100, GPT-5.1 60/100), so choose by what matters most for your work: GPT-5 for raw capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5Capabilities Index (ECI): GPT-5 150.0 · GPT-5.1 149.7
  • Lowest priceSame priceGPT-5 $3.44 · GPT-5.1 $3.44 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGPT-5 400,000 · GPT-5.1 400,000 tokens
  • Widest inputsSame inputsGPT-5: Text, Images · GPT-5.1: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5GPT-5.1
CapabilityCapabilities Index (ECI)50%7878
Price25%2424
Inputs & features15%7070
Context window10%4444
Overall100%60/10060/100
02 — Side by side

Every spec in one table

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

GPT-5 vs GPT-5.1 specifications side by side
SpecificationGPT-5OpenAIGPT-5.1OpenAI
Capability
Capabilities Index (ECI)150.0 (best)149.7
ECI rank#50 of 148 (best)#52 of 148
GPQA DiamondGraduate-level science questions86.2%87.6% (best)
FrontierMath Tiers 1–3Research-level mathematics55.4%—
OTIS Mock AIME 2024–2025Competition mathematics91.4% (best)88.6%
SWE-bench VerifiedFixing real GitHub issues73.6% (best)68.0%
SimpleQA VerifiedShort factual questions50.1% (best)48.0%
Price per million tokens
Input$1.25$1.25
Output$10.00$10.00
Cached input$0.125$0.125
Blended (3:1)$3.44$3.44
Long-context rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial OpenAI API
Limits
Context window400,000 tokens400,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesminimal · low · medium · highYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-5gpt-5.1
API providers24 (best)21
ReleasedAug 7, 2025Nov 13, 2025
Knowledge cutoffSep 30, 2024Sep 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.

  • GPT-5$32.50
  • GPT-5.1$32.50
04 — Questions

Which should you choose?

Which is better: GPT-5 or GPT-5.1?

It is close. Our weighted score puts them within a point (GPT-5 60/100, GPT-5.1 60/100), so choose by what matters most for your work: GPT-5 for raw capability. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5 or GPT-5.1?

GPT-5 and GPT-5.1 cost the same: $1.25 input / $10.00 output per million tokens.

Which scores higher on benchmarks?

GPT-5 scores higher on the Capabilities Index (ECI): GPT-5 150.0 (#50 of 148) and GPT-5.1 149.7 (#52 of 148). On individual benchmarks: GPQA Diamond — GPT-5.1 87.6%, GPT-5 86.2%; OTIS Mock AIME 2024–2025 — GPT-5 91.4%, GPT-5.1 88.6%; SWE-bench Verified — GPT-5 73.6%, GPT-5.1 68.0%; SimpleQA Verified — GPT-5 50.1%, GPT-5.1 48.0%.

Which is better for coding?

GPT-5 resolves more real GitHub issues on SWE-bench Verified: GPT-5 73.6% and GPT-5.1 68.0%. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-5 and GPT-5.1 share the same 400,000-token context window. Maximum output per response: GPT-5 up to 128,000, GPT-5.1 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5 accepts text and images; GPT-5.1 accepts text and images. They handle the same number of input types.

Are any of these open source?

No. GPT-5 and GPT-5.1 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.1 is the newest, released Nov 13, 2025. GPT-5 came out Aug 7, 2025. Knowledge cutoff: GPT-5 Sep 30, 2024, 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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