GPT-5.1 Codex High vs Mistral Medium 3.5

    Comparison

    As of August 25, 2026, Mistral Medium 3.5 is 20% cheaper per million tokens than GPT-5.1 Codex High. GPT-5.1 Codex High is $1.25 / $10.00 per million input/output tokens versus Mistral Medium 3.5 at $1.50 / $7.50. Sources: https://developers.openai.com/api/docs/pricing and https://docs.mistral.ai/platform/pricing/

    Sources: OpenAI API pricing (https://developers.openai.com/api/docs/pricing); Mistral AI pricing (https://docs.mistral.ai/platform/pricing/)

    GPT-5.1 Codex High

    OpenAI

    $11.25blended / 1M

    Input

    $1.25

    Output

    $10.00

    400K ctx|Proprietary
    20%
    cheaper
    Better value

    Mistral Medium 3.5

    Mistral

    $9.00blended / 1M

    Input

    $1.50

    Output

    $7.50

    256K ctx|Open Source
    Save $2.25 per million tokens by choosing Mistral Medium 3.5 over GPT-5.1 Codex High.

    GPT-5.1 Codex High vs Mistral Medium 3.5 comparison

    Token pricing, specs, and benchmarks side by side

    Shared benchmarks

    Each bar is share of the current leader on that eval. Click a row to open the board.

    GPT-5.1 Codex HighMistral Medium 3.5

    Score vs price

    AIME 2025. Left is cheaper. Up is a higher score. The line is the best score you can buy at each price.

    Best score at each priceGPT-5.1 Codex HighMistral Medium 3.5
    Metric
    GPT-5.1 Codex High
    Mistral Medium 3.5
    Provider
    Provider
    OpenAI
    Mistral
    License
    Proprietary
    Open Source
    Release Date
    2025-11-12
    2026-04-29
    Pricing (per 1M tokens)
    Input Price-17%
    $1.25
    $1.50
    Output Price+33%
    $10.00
    $7.50
    Blended (1M + 1M)
    $11.25
    $9.00
    Model Details
    Context Window
    400K
    256K
    Max Output Tokens
    128K
    256K
    Knowledge Cutoff
    N/A
    N/A
    Throughput
    50 tok/s
    1 tok/s
    Benchmarks
    34.9%
    39.6%
    48.6%
    69%
    96.7%
    86.3%
    66.9%
    95.8%
    58.8%
    0%
    11.2%
    33.8%
    67.7%
    75.3%
    37.6%
    13.4%
    76.1%
    91.4%
    68.0%
    Benchmark Wins
    GPT-5.1 Codex High 1|0 Mistral Medium 3.5

    Verdict

    GPT-5.1 Codex High vs Mistral Medium 3.5: the bottom line

    Mistral Medium 3.5 offers significantly lower pricing, while GPT-5.1 Codex High leads on benchmark performance. Your choice depends on whether cost efficiency or raw capability matters more for your use case.

    GPT-5.1 Codex High vs Mistral Medium 3.5 FAQ

    Which is cheaper, GPT-5.1 Codex High or Mistral Medium 3.5?

    As of August 25, 2026, Mistral Medium 3.5 is 20% cheaper on blended LLM API pricing. Mistral Medium 3.5 costs $1.50 per million input tokens and $7.50 per million output tokens ($9.00 blended 1M-in + 1M-out). GPT-5.1 Codex High costs $1.25 / $10.00 per million tokens ($11.25 blended). Sources: https://developers.openai.com/api/docs/pricing and https://docs.mistral.ai/platform/pricing/. The cheapest LLM for your app still depends on how many output tokens you generate.

    How much does GPT-5.1 Codex High vs Mistral Medium 3.5 cost per million tokens?

    GPT-5.1 Codex High OpenAI API pricing is $1.25 input and $10.00 output per million tokens via OpenAI. Mistral Medium 3.5 Mistral API pricing is $1.50 input and $7.50 output per million tokens via Mistral AI. Use those four numbers, not ChatGPT Plus or Claude Pro subscription prices, when you are comparing APIs.

    Which is better for coding, GPT-5.1 Codex High or Mistral Medium 3.5?

    Mistral Medium 3.5 has a published SWE-bench Verified score of 77.6%. GPT-5.1 Codex High does not have that eval on this page yet.

    What is the context window for GPT-5.1 Codex High vs Mistral Medium 3.5?

    GPT-5.1 Codex High supports a 400K token context window, while Mistral Medium 3.5 supports 256K tokens. GPT-5.1 Codex High offers a larger context window. Filling a larger window bills more input tokens, so the cheaper-per-million model can still cost more on long documents.

    Which model performs better on benchmarks, GPT-5.1 Codex High or Mistral Medium 3.5?

    GPT-5.1 Codex High leads on 1 of 1 shared benchmarks versus Mistral Medium 3.5's 0 wins. Check the comparison table for GPQA Diamond, SWE-bench, MMLU, HLE, and the other evals we track. Token price and benchmark score together are the usual LLM comparison, not either number alone.

    Is GPT-5.1 Codex High or Mistral Medium 3.5 better for production use?

    Both GPT-5.1 Codex High and Mistral Medium 3.5 are production API models. For cost-sensitive production traffic, Mistral Medium 3.5 has better economics on the blended 1M-in + 1M-out scale. For maximum capability, weight the benchmark table for your domain. Many production stacks route cheap models for drafts and a frontier model for the hard turn, which is usually cheaper than sending everything to the expensive API.

    Can I switch between GPT-5.1 Codex High and Mistral Medium 3.5 in my app?

    Yes. Call GPT-5.1 Codex High through OpenAI and Mistral Medium 3.5 through Mistral AI with separate API keys, or through a gateway that already wraps both. Keep prompts in tokens, not characters, when you estimate the invoice. AnotherWrapper templates can swap providers without rewriting auth and billing.

    How accurate is this GPT-5.1 Codex High vs Mistral Medium 3.5 pricing data?

    List rates are the latest published OpenAI API pricing and Mistral API pricing, quoted per million tokens. Official rate sheets: https://developers.openai.com/api/docs/pricing and https://docs.mistral.ai/platform/pricing/. Prompt caching, batch APIs, and committed-use discounts can change the invoice. Benchmark scores are from official publications and independent evals, updated as new numbers land.

    What is the output token limit for GPT-5.1 Codex High and Mistral Medium 3.5?

    GPT-5.1 Codex High supports up to 128K output tokens per request, while Mistral Medium 3.5 supports up to 256K output tokens. Output tokens are usually the expensive half of API pricing, so a higher max output cap is a capability, not a discount.

    Which model has better throughput, GPT-5.1 Codex High or Mistral Medium 3.5?

    GPT-5.1 Codex High runs at approximately 50 tokens/second while Mistral Medium 3.5 runs at 1 tokens/second. GPT-5.1 Codex High is faster in raw throughput. Throughput (tokens per second) and time-to-first-token are why two models with the same per-million-token price can still feel different in chat and agents.

    How do I switch the models in this GPT-5.1 Codex High vs Mistral Medium 3.5 comparison?

    Use the model pickers at the top of this LLM comparison. Search any model in the index and the URL updates. Open GPT-5.1 Codex High or Mistral Medium 3.5 from the sidebar for the single-model API pricing page, or go back to the LLM pricing table to sort by cheapest blended cost.

    GPT-5.1 Codex High vs Mistral Medium 3.5 pricing

    This comparison covers API pricing, context window, throughput, and benchmark scores. GPT-5.1 Codex High costs $1.25/M input and $10.00/M output. Mistral Medium 3.5 costs $1.50/M input and $7.50/M output via Mistral AI.

    Rank both on the LLM leaderboard, SWE-bench, and Humanity's Last Exam.

    The index

    All Large Language Models

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