ZMIME
Comparison · 3 models · Updated Oct 4, 2026

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

Too close to call on our weighted score (Gemini 3.1 Pro Preview 68, GPT-5.4 65, GPT-5.3 Codex 64). The right pick depends on what you value most.

  1. 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

    Released Mar 5, 2026

    65/100
    • ECI156.9
    • Price$2.50 / $15.00
    • Context1.05M
01 — Verdict

Too close to call

It is close. Our weighted score puts them within 3 points (Gemini 3.1 Pro Preview 68/100, GPT-5.4 65/100, GPT-5.3 Codex 64/100), so choose by what matters most for your work: GPT-5.4 for raw capability and Gemini 3.1 Pro Preview on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.4Capabilities Index (ECI): GPT-5.4 156.9 · GPT-5.3 Codex 156.8 · Gemini 3.1 Pro Preview 154.8
  • Lowest priceGemini 3.1 Pro PreviewGemini 3.1 Pro Preview $4.50 · GPT-5.3 Codex $4.81 · GPT-5.4 $5.63 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.4 and Gemini 3.1 Pro PreviewGPT-5.4 1,050,000 · Gemini 3.1 Pro Preview 1,048,576 · GPT-5.3 Codex 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: Text, Images, PDFs
  • 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
CapabilityCapabilities Index (ECI)50%848787
Price25%191814
Inputs & features15%1008080
Context window10%614461
Overall100%68/10064/10065/100
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 specifications side by side
SpecificationGemini 3.1 Pro PreviewGoogleGPT-5.3 CodexOpenAIGPT-5.4OpenAI
Capability
Capabilities Index (ECI)154.8156.8156.9 (best)
ECI rank#31 of 148#18 of 148#16 of 148 (best)
GPQA DiamondGraduate-level science questions94.4% (best)—93.3%
FrontierMath Tiers 1–3Research-level mathematics59.7%—78.6% (best)
OTIS Mock AIME 2024–2025Competition mathematics95.6%—97.8% (best)
SWE-bench VerifiedFixing real GitHub issues75.6%74.8%76.9% (best)
SimpleQA VerifiedShort factual questions73.5% (best)—45.1%
Price per million tokens
Input$2.00$1.75 (best)$2.50
Output$12.00 (best)$14.00$15.00
Cached input$0.20$0.175 (best)$0.25
Blended (3:1)$4.50 (best)$4.81$5.63
Long-context rateOver 200K: $4.00 / $18.00Same rateOver 272K: $5.00 / $22.50
Price sourceOfficial Google APIOfficial OpenAI APIOfficial OpenAI API
Limits
Context window1,048,576 tokens400,000 tokens1,050,000 tokens (best)
Max output65,536 tokens128,000 tokens (best)128,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesYes
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
API providers261936 (best)
ReleasedFeb 19, 2026Feb 5, 2026Mar 5, 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$55.00
04 — Questions

Which should you choose?

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

It is close. Our weighted score puts them within 3 points (Gemini 3.1 Pro Preview 68/100, GPT-5.4 65/100, GPT-5.3 Codex 64/100), so choose by what matters most for your work: GPT-5.4 for raw capability and Gemini 3.1 Pro Preview 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?

Gemini 3.1 Pro Preview is cheaper at $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); GPT-5.4 costs $2.50 input / $15.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $4.50 per million tokens for Gemini 3.1 Pro Preview versus $4.81 for GPT-5.3 Codex (1.1× as much) and $5.63 for GPT-5.4 (1.3× as much).

Which scores higher on benchmarks?

GPT-5.4 scores higher on the Capabilities Index (ECI): GPT-5.4 156.9 (#16 of 148), GPT-5.3 Codex 156.8 (#18 of 148) and Gemini 3.1 Pro Preview 154.8 (#31 of 148). The confidence ranges of the top two overlap (154.9–159.1 vs 153.5–160.8), so treat the gap as small. On individual benchmarks: SWE-bench Verified — GPT-5.4 76.9%, Gemini 3.1 Pro Preview 75.6%, GPT-5.3 Codex 74.8%.

Which is better for coding?

GPT-5.4 resolves more real GitHub issues on SWE-bench Verified: GPT-5.4 76.9%, Gemini 3.1 Pro Preview 75.6% and GPT-5.3 Codex 74.8%. All three support tool calling for agent workflows.

Which has the bigger context window?

GPT-5.4 and Gemini 3.1 Pro Preview have the largest context windows (1,050,000 and 1,048,576 tokens), against 400,000 for GPT-5.3 Codex. Maximum output per response: Gemini 3.1 Pro Preview up to 65,536, GPT-5.3 Codex up to 128,000, GPT-5.4 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 accepts text, images and PDFs. 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 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.4 is the newest, released Mar 5, 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 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.