GPT-5.1 Codex Mini vs GPT-5.6 Luna

    Comparison

    As of August 20, 2026, GPT-5.6 Luna is 38% cheaper per million tokens than GPT-5.1 Codex Mini. GPT-5.1 Codex Mini is $0.25 / $2.00 per million input/output tokens versus GPT-5.6 Luna at $0.20 / $1.20. Source: https://developers.openai.com/api/docs/pricing

    Source: OpenAI API pricing (https://developers.openai.com/api/docs/pricing)

    GPT-5.1 Codex Mini

    OpenAI

    $2.25blended / 1M

    Input

    $0.25

    Output

    $2.00

    400K ctx|Proprietary
    38%
    cheaper
    Better value

    GPT-5.6 Luna

    OpenAI

    $1.40blended / 1M

    Input

    $0.20

    Output

    $1.20

    1.1M ctx|Proprietary
    Save $0.85 per million tokens by choosing GPT-5.6 Luna over GPT-5.1 Codex Mini.

    GPT-5.1 Codex Mini vs GPT-5.6 Luna comparison

    Token pricing, specs, and benchmarks side by side

    Metric
    GPT-5.1 Codex Mini
    GPT-5.6 Luna
    Provider
    Provider
    OpenAI
    OpenAI
    License
    Proprietary
    Proprietary
    Release Date
    2025-11-12
    2026-07-09
    Pricing (per 1M tokens)
    Input Price+25%
    $0.25
    $0.20
    Output Price+67%
    $2.00
    $1.20
    Blended (1M + 1M)
    $2.25
    $1.40
    Model Details
    Context Window
    400K
    1.1M
    Max Output Tokens
    128K
    128K
    Knowledge Cutoff
    2024-09-30
    2026-02-16
    Throughput
    200 tok/s
    48.45216448188169 tok/s
    Benchmarks
    92.3%
    63.6%
    67.2%
    67.2%
    52.5%
    1244
    1522.94
    83.3%
    41.7%
    59.5%
    53.4%
    78.4%
    78.6%
    42.1%
    40%
    85.4%
    85.0%
    0.2%
    63.1%
    64.2%
    20.6%
    83.9%
    67.1%
    33.2%
    12.4%
    39.8%
    22.7%
    55.8%
    72.9%
    22.4%
    51.2%
    30.4%
    42.4%
    84.4%
    86.0%
    41.3%
    1.7%
    45.6%
    41.9%
    44.2%
    46.8%
    60.5%
    76.2%
    Benchmark Wins
    GPT-5.1 Codex Mini 2|1 GPT-5.6 Luna

    Verdict

    GPT-5.1 Codex Mini vs GPT-5.6 Luna: the bottom line

    GPT-5.6 Luna offers significantly lower pricing, while GPT-5.1 Codex Mini leads on benchmark performance. Your choice depends on whether cost efficiency or raw capability matters more for your use case.

    GPT-5.1 Codex Mini vs GPT-5.6 Luna FAQ

    Which is cheaper, GPT-5.1 Codex Mini or GPT-5.6 Luna?

    As of August 20, 2026, GPT-5.6 Luna is 38% cheaper on blended LLM API pricing. GPT-5.6 Luna costs $0.20 per million input tokens and $1.20 per million output tokens ($1.40 blended 1M-in + 1M-out). GPT-5.1 Codex Mini costs $0.25 / $2.00 per million tokens ($2.25 blended). Sources: https://developers.openai.com/api/docs/pricing and https://developers.openai.com/api/docs/pricing. The cheapest LLM for your app still depends on how many output tokens you generate.

    How much does GPT-5.1 Codex Mini vs GPT-5.6 Luna cost per million tokens?

    GPT-5.1 Codex Mini OpenAI API pricing is $0.25 input and $2.00 output per million tokens via OpenAI. GPT-5.6 Luna OpenAI API pricing is $0.20 input and $1.20 output per million tokens via OpenAI. 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 Mini or GPT-5.6 Luna?

    GPT-5.6 Luna has a published SWE-bench Verified score of 93%. GPT-5.1 Codex Mini does not have that eval on this page yet.

    What is the context window for GPT-5.1 Codex Mini vs GPT-5.6 Luna?

    GPT-5.1 Codex Mini supports a 400K token context window, while GPT-5.6 Luna supports 1M tokens. GPT-5.6 Luna 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 Mini or GPT-5.6 Luna?

    GPT-5.1 Codex Mini leads on 2 of 3 shared benchmarks versus GPT-5.6 Luna's 1 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 Mini or GPT-5.6 Luna better for production use?

    Both GPT-5.1 Codex Mini and GPT-5.6 Luna are production API models. For cost-sensitive production traffic, GPT-5.6 Luna 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 Mini and GPT-5.6 Luna in my app?

    Yes. Call GPT-5.1 Codex Mini through OpenAI and GPT-5.6 Luna through OpenAI 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 Mini vs GPT-5.6 Luna pricing data?

    List rates are the latest published OpenAI API pricing and OpenAI API pricing, quoted per million tokens. Official rate sheets: https://developers.openai.com/api/docs/pricing and https://developers.openai.com/api/docs/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 Mini and GPT-5.6 Luna?

    GPT-5.1 Codex Mini supports up to 128K output tokens per request, while GPT-5.6 Luna supports up to 128K 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 Mini or GPT-5.6 Luna?

    GPT-5.1 Codex Mini runs at approximately 200 tokens/second while GPT-5.6 Luna runs at 48.45216448188169 tokens/second. GPT-5.1 Codex Mini 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 Mini vs GPT-5.6 Luna 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 Mini or GPT-5.6 Luna 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 Mini vs GPT-5.6 Luna pricing

    This comparison covers API pricing, context window, throughput, and benchmark scores. GPT-5.1 Codex Mini costs $0.25/M input and $2.00/M output. GPT-5.6 Luna costs $0.20/M input and $1.20/M output.

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

    The index

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