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Comparison · 3 models · Updated Oct 4, 2026

Gemini 3.1 Pro Preview vs GPT-5.3 Codex vs GPT-5.4 mini

Gemini 3.1 Pro Preview comes out ahead, 68 to 64 and 63 on our weighted score, though GPT-5.4 mini is 2.7× cheaper per token.

  1. Our pick

    Google

    Gemini 3.1 Pro Preview

    Released Feb 19, 2026

    68/100
    • ECI154.8
    • Price$2.00 / $12.00
    • Context1.05M
  2. OpenAI

    GPT-5.3 Codex

    Released Feb 5, 2026

    64/100
    • ECI156.8
    • Price$1.75 / $14.00
    • Context400K
  3. OpenAI

    GPT-5.4 mini

    Released Mar 17, 2026

    63/100
    • ECI148.8
    • Price$0.75 / $4.50
    • Context400K
01 — Verdict

Gemini 3.1 Pro Preview is our pick

Gemini 3.1 Pro Preview is the better all-round choice, scoring 68/100 against GPT-5.3 Codex (64) and GPT-5.4 mini (63). It leads on inputs & features and context window. GPT-5.3 Codex wins on capability. GPT-5.4 mini wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.3 CodexCapabilities Index (ECI): GPT-5.3 Codex 156.8 · Gemini 3.1 Pro Preview 154.8 · GPT-5.4 mini 148.8
  • Lowest priceGPT-5.4 miniGPT-5.4 mini $1.69 · Gemini 3.1 Pro Preview $4.50 · GPT-5.3 Codex $4.81 per 1M tokens (3:1 blend)
  • Longest contextGemini 3.1 Pro PreviewGemini 3.1 Pro Preview 1,048,576 · GPT-5.3 Codex 400,000 · GPT-5.4 mini 400,000 tokens
  • Widest inputsGemini 3.1 Pro PreviewGemini 3.1 Pro Preview: Text, Images, PDFs, Audio, Video · GPT-5.3 Codex: Text, Images, PDFs · GPT-5.4 mini: Text, Images
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightGemini 3.1 Pro PreviewGPT-5.3 CodexGPT-5.4 mini
CapabilityCapabilities Index (ECI)50%848777
Price25%191839
Inputs & features15%1008070
Context window10%614444
Overall100%68/10064/10063/100
02 — Side by side

Every spec in one table

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

Gemini 3.1 Pro Preview vs GPT-5.3 Codex vs GPT-5.4 mini specifications side by side
SpecificationGemini 3.1 Pro PreviewGoogleGPT-5.3 CodexOpenAIGPT-5.4 miniOpenAI
Capability
Capabilities Index (ECI)154.8156.8 (best)148.8
ECI rank#31 of 148#18 of 148 (best)#56 of 148
GPQA DiamondGraduate-level science questions94.4% (best)—86.9%
FrontierMath Tiers 1–3Research-level mathematics59.7% (best)—51.2%
OTIS Mock AIME 2024–2025Competition mathematics95.6% (best)—88.9%
SWE-bench VerifiedFixing real GitHub issues75.6% (best)74.8%—
SimpleQA VerifiedShort factual questions73.5% (best)—29.4%
Price per million tokens
Input$2.00$1.75$0.75 (best)
Output$12.00$14.00$4.50 (best)
Cached input$0.20$0.175$0.075 (best)
Blended (3:1)$4.50$4.81$1.69 (best)
Long-context rateOver 200K: $4.00 / $18.00Same rateSame rate
Price sourceOfficial Google APIOfficial OpenAI APIOfficial OpenAI API
Limits
Context window1,048,576 tokens (best)400,000 tokens400,000 tokens
Max output65,536 tokens128,000 tokens (best)128,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesNo
AudioYesNoNo
VideoYesNoNo
ReasoningYeslow · medium · highYeslow · medium · high · xhighYeslow · medium · high · xhigh
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model IDgemini-3.1-pro-previewgpt-5.3-codexgpt-5.4-mini
API providers261929 (best)
ReleasedFeb 19, 2026Feb 5, 2026Mar 17, 2026
Knowledge cutoffJan 2025Aug 31, 2025Aug 31, 2025
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 3.1 Pro Preview$44.00
  • GPT-5.3 Codex$45.50
  • GPT-5.4 mini$16.50
04 — Questions

Which should you choose?

Which is better: Gemini 3.1 Pro Preview, GPT-5.3 Codex or GPT-5.4 mini?

Gemini 3.1 Pro Preview is the better all-round choice, scoring 68/100 against GPT-5.3 Codex (64) and GPT-5.4 mini (63). It leads on inputs & features and context window. GPT-5.3 Codex wins on capability. GPT-5.4 mini wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Gemini 3.1 Pro Preview, GPT-5.3 Codex or GPT-5.4 mini?

GPT-5.4 mini is cheaper at $0.75 input / $4.50 output per million tokens (official OpenAI API price). Gemini 3.1 Pro Preview costs $2.00 input / $12.00 output per million tokens (official Google API price); GPT-5.3 Codex costs $1.75 input / $14.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $1.69 per million tokens for GPT-5.4 mini versus $4.50 for Gemini 3.1 Pro Preview (2.7× as much) and $4.81 for GPT-5.3 Codex (2.9× as much).

Which scores higher on benchmarks?

GPT-5.3 Codex scores higher on the Capabilities Index (ECI): GPT-5.3 Codex 156.8 (#18 of 148), Gemini 3.1 Pro Preview 154.8 (#31 of 148) and GPT-5.4 mini 148.8 (#56 of 148). The confidence ranges of the top two overlap (153.5–160.8 vs 152.6–157.3), so treat the gap as small.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.4 mini yet, so there is no like-for-like coding score. On overall capability, GPT-5.3 Codex leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

Gemini 3.1 Pro Preview has the largest context window at 1,048,576 tokens, against 400,000 for GPT-5.3 Codex and 400,000 for GPT-5.4 mini. Maximum output per response: Gemini 3.1 Pro Preview up to 65,536, GPT-5.3 Codex up to 128,000, GPT-5.4 mini up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Gemini 3.1 Pro Preview accepts text, images, PDFs, audio and video; GPT-5.3 Codex accepts text, images and PDFs; GPT-5.4 mini accepts text and images. Gemini 3.1 Pro Preview handles the widest range of inputs.

Are any of these open source?

No. Gemini 3.1 Pro Preview, GPT-5.3 Codex and GPT-5.4 mini are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.4 mini is the newest, released Mar 17, 2026. Gemini 3.1 Pro Preview came out Feb 19, 2026; GPT-5.3 Codex came out Feb 5, 2026. Knowledge cutoff: Gemini 3.1 Pro Preview Jan 2025, GPT-5.3 Codex Aug 31, 2025, GPT-5.4 mini Aug 31, 2025.

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.