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Comparison · 2 models · Updated Oct 4, 2026

GPT-5.1 Codex Max vs GPT-5.1 Codex

Too close to call on our weighted score (GPT-5.1 Codex Max 42, GPT-5.1 Codex 42). The right pick depends on what you value most.

  1. OpenAI

    GPT-5.1 Codex Max

    Released Nov 13, 2025

    42/100
    • ECI—
    • Price$1.25 / $10.00
    • Context400K
    Full specs Remove GPT-5.1 Codex Max

  2. OpenAI

    GPT-5.1 Codex

    Released Nov 13, 2025

    42/100
    • ECI—
    • Price$1.25 / $10.00
    • Context400K
    Full specs Remove GPT-5.1 Codex

  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-5.1 Codex Max 42/100, GPT-5.1 Codex 42/100), so choose by what matters most for your work: GPT-5.1 Codex Max on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceSame priceGPT-5.1 Codex Max $3.44 · GPT-5.1 Codex $3.44 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGPT-5.1 Codex Max 400,000 · GPT-5.1 Codex 400,000 tokens
  • Widest inputsSame inputsGPT-5.1 Codex Max: Text, Images · GPT-5.1 Codex: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.1 Codex MaxGPT-5.1 Codex
Price50%2424
Inputs & features30%7070
Context window20%4444
Overall100%42/10042/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

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

GPT-5.1 Codex Max vs GPT-5.1 Codex specifications side by side
SpecificationGPT-5.1 Codex MaxOpenAIGPT-5.1 CodexOpenAI
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$1.25$1.25
Output$10.00$10.00
Cached input——
Blended (3:1)$3.44$3.44
Long-context rateSame rateSame rate
Price sourceMedian of 8 providersMedian of 10 providers
Limits
Context window400,000 tokens400,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYes
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model ID——
API providers810 (best)
ReleasedNov 13, 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-5.1 Codex Max$32.50
  • GPT-5.1 Codex$32.50
04 — Questions

Which should you choose?

Which is better: GPT-5.1 Codex Max or GPT-5.1 Codex?

It is close. Our weighted score puts them within a point (GPT-5.1 Codex Max 42/100, GPT-5.1 Codex 42/100), so choose by what matters most for your work: GPT-5.1 Codex Max on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, GPT-5.1 Codex Max or GPT-5.1 Codex?

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

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. GPT-5.1 Codex Max has not been scored yet and GPT-5.1 Codex has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.1 Codex Max and GPT-5.1 Codex yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

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

Which can read images, PDFs, audio or video?

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

Are any of these open source?

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

Which is newer?

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