ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GPT-5.1 Codex mini vs Mistral Medium 3.1

GPT-5.1 Codex mini comes out ahead, 59 to 50 on our weighted score, and it is the cheaper option too.

  1. Our pick

    OpenAI

    GPT-5.1 Codex mini

    Released Nov 13, 2025

    59/100
    • ECI—
    • Price$0.25 / $2.00
    • Context400K
  2. Mistral AI

    Mistral Medium 3.1

    Released Aug 12, 2025

    50/100
    • ECI—
    • Price$0.40 / $2.00
    • Context262K
  3. Add a model

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01 — Verdict

GPT-5.1 Codex mini is our pick

GPT-5.1 Codex mini is the better all-round choice, scoring 59/100 against Mistral Medium 3.1 (50). It leads on price, inputs & features and context window. 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 priceGPT-5.1 Codex miniGPT-5.1 Codex mini $0.688 · Mistral Medium 3.1 $0.80 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.1 Codex miniGPT-5.1 Codex mini 400,000 · Mistral Medium 3.1 262,144 tokens
  • Widest inputsSame inputsGPT-5.1 Codex mini: Text, Images · Mistral Medium 3.1: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.1 Codex miniMistral Medium 3.1
Price50%5854
Inputs & features30%7050
Context window20%4437
Overall100%59/10050/100

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 mini vs Mistral Medium 3.1 specifications side by side
SpecificationGPT-5.1 Codex miniOpenAIMistral Medium 3.1Mistral AI
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.25 (best)$0.40
Output$2.00$2.00
Cached input——
Blended (3:1)$0.688 (best)$0.80
Long-context rateSame rateSame rate
Price sourceMedian of 10 providersOfficial Mistral API
Limits
Context window400,000 tokens (best)262,144 tokens
Max output128,000 tokens262,144 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesNo
Tool callingYesYes
Structured outputYesNo
Availability
WeightsProprietaryProprietary
API model ID—mistral-medium-2508
API providers10 (best)1
ReleasedNov 13, 2025Aug 12, 2025
Knowledge cutoffSep 30, 2024May 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.

  • GPT-5.1 Codex mini$6.50
  • Mistral Medium 3.1$8.00
04 — Questions

Which should you choose?

Which is better: GPT-5.1 Codex mini or Mistral Medium 3.1?

GPT-5.1 Codex mini is the better all-round choice, scoring 59/100 against Mistral Medium 3.1 (50). It leads on price, inputs & features and context window. 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 mini or Mistral Medium 3.1?

GPT-5.1 Codex mini is cheaper at $0.25 input / $2.00 output per million tokens (median across 10 API providers). Mistral Medium 3.1 costs $0.40 input / $2.00 output per million tokens (official Mistral API price). At a typical mix of three input tokens to one output token, that is $0.688 per million tokens for GPT-5.1 Codex mini versus $0.80 for Mistral Medium 3.1 (1.2× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. GPT-5.1 Codex mini has not been scored yet and Mistral Medium 3.1 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.1 Codex mini and Mistral Medium 3.1 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 mini has the largest context window at 400,000 tokens, against 262,144 for Mistral Medium 3.1. Maximum output per response: GPT-5.1 Codex mini up to 128,000, Mistral Medium 3.1 up to 262,144 tokens.

Which can read images, PDFs, audio or video?

GPT-5.1 Codex mini accepts text and images; Mistral Medium 3.1 accepts text and images. They handle the same number of input types.

Are any of these open source?

No. GPT-5.1 Codex mini and Mistral Medium 3.1 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.1 Codex mini is the newest, released Nov 13, 2025. Mistral Medium 3.1 came out Aug 12, 2025. Knowledge cutoff: GPT-5.1 Codex mini Sep 30, 2024, Mistral Medium 3.1 May 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.