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Comparison · 2 models · Updated Oct 4, 2026

Gemini 3 Pro Preview vs GPT-5.1

Gemini 3 Pro Preview comes out ahead, 67 to 60 on our weighted score, though GPT-5.1 is 24% cheaper per token.

  1. Our pick

    Google

    Gemini 3 Pro Preview

    Released Nov 18, 2025

    67/100
    • ECI153.0
    • Price$2.00 / $12.00
    • Context1.05M
    Full specs Remove Gemini 3 Pro Preview

  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

Gemini 3 Pro Preview is our pick

Gemini 3 Pro Preview is the better all-round choice, scoring 67/100 against GPT-5.1 (60). It leads on capability, inputs & features and context window. GPT-5.1 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGemini 3 Pro PreviewCapabilities Index (ECI): Gemini 3 Pro Preview 153.0 · GPT-5.1 149.7
  • Lowest priceGPT-5.1GPT-5.1 $3.44 · Gemini 3 Pro Preview $4.50 per 1M tokens (3:1 blend)
  • Longest contextGemini 3 Pro PreviewGemini 3 Pro Preview 1,048,576 · GPT-5.1 400,000 tokens
  • Widest inputsGemini 3 Pro PreviewGemini 3 Pro Preview: Text, Images, PDFs, Audio, Video · GPT-5.1: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGemini 3 Pro PreviewGPT-5.1
CapabilityCapabilities Index (ECI)50%8278
Price25%1924
Inputs & features15%10070
Context window10%6144
Overall100%67/10060/100
02 — Side by side

Every spec in one table

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

Gemini 3 Pro Preview vs GPT-5.1 specifications side by side
SpecificationGemini 3 Pro PreviewGoogleGPT-5.1OpenAI
Capability
Capabilities Index (ECI)153.0 (best)149.7
ECI rank#39 of 148 (best)#52 of 148
GPQA DiamondGraduate-level science questions92.6% (best)87.6%
OTIS Mock AIME 2024–2025Competition mathematics91.4% (best)88.6%
SWE-bench VerifiedFixing real GitHub issues72.9% (best)68.0%
SimpleQA VerifiedShort factual questions—48.0%
Price per million tokens
Input$2.00$1.25 (best)
Output$12.00$10.00 (best)
Cached input—$0.125
Blended (3:1)$4.50$3.44 (best)
Long-context rateSame rateSame rate
Price sourceMedian of 2 providersOfficial OpenAI API
Limits
Context window1,048,576 tokens (best)400,000 tokens
Max output65,536 tokens128,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioYesNo
VideoYesNo
ReasoningYesYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model ID—gpt-5.1
API providers321 (best)
ReleasedNov 18, 2025Nov 13, 2025
Knowledge cutoffJan 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.

  • Gemini 3 Pro Preview$44.00
  • GPT-5.1$32.50
04 — Questions

Which should you choose?

Which is better: Gemini 3 Pro Preview or GPT-5.1?

Gemini 3 Pro Preview is the better all-round choice, scoring 67/100 against GPT-5.1 (60). It leads on capability, inputs & features and context window. GPT-5.1 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Gemini 3 Pro Preview or GPT-5.1?

GPT-5.1 is cheaper at $1.25 input / $10.00 output per million tokens (official OpenAI API price). Gemini 3 Pro Preview costs $2.00 input / $12.00 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for GPT-5.1 versus $4.50 for Gemini 3 Pro Preview (1.3× as much).

Which scores higher on benchmarks?

Gemini 3 Pro Preview scores higher on the Capabilities Index (ECI): Gemini 3 Pro Preview 153.0 (#39 of 148) and GPT-5.1 149.7 (#52 of 148). The confidence ranges of the top two overlap (150.6–155.2 vs 148.3–151.1), so treat the gap as small. On individual benchmarks: GPQA Diamond — Gemini 3 Pro Preview 92.6%, GPT-5.1 87.6%; OTIS Mock AIME 2024–2025 — Gemini 3 Pro Preview 91.4%, GPT-5.1 88.6%; SWE-bench Verified — Gemini 3 Pro Preview 72.9%, GPT-5.1 68.0%.

Which is better for coding?

Gemini 3 Pro Preview resolves more real GitHub issues on SWE-bench Verified: Gemini 3 Pro Preview 72.9% and GPT-5.1 68.0%. Both support tool calling for agent workflows.

Which has the bigger context window?

Gemini 3 Pro Preview has the largest context window at 1,048,576 tokens, against 400,000 for GPT-5.1. Maximum output per response: Gemini 3 Pro Preview up to 65,536, GPT-5.1 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Gemini 3 Pro Preview accepts text, images, PDFs, audio and video; GPT-5.1 accepts text and images. Gemini 3 Pro Preview handles the widest range of inputs.

Are any of these open source?

No. Gemini 3 Pro Preview and GPT-5.1 are proprietary and only available through APIs and apps.

Which is newer?

Gemini 3 Pro Preview is the newest, released Nov 18, 2025. GPT-5.1 came out Nov 13, 2025. Knowledge cutoff: Gemini 3 Pro Preview Jan 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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