DeepSeek-V3.1 vs GPT-5.1 Codex High

    Comparison

    As of August 20, 2026, DeepSeek-V3.1 is 89% cheaper per million tokens than GPT-5.1 Codex High. DeepSeek-V3.1 is $0.27 / $1.00 per million input/output tokens versus GPT-5.1 Codex High at $1.25 / $10.00. Sources: https://api-docs.deepseek.com/quick_start/pricing and https://developers.openai.com/api/docs/pricing

    Sources: DeepSeek API pricing (https://api-docs.deepseek.com/quick_start/pricing); OpenAI API pricing (https://developers.openai.com/api/docs/pricing)

    Better value

    DeepSeek-V3.1

    DeepSeek

    $1.27blended / 1M

    Input

    $0.27

    Output

    $1.00

    163.8K ctx|Open Source
    89%
    cheaper

    GPT-5.1 Codex High

    OpenAI

    $11.25blended / 1M

    Input

    $1.25

    Output

    $10.00

    400K ctx|Proprietary
    Save $9.98 per million tokens by choosing DeepSeek-V3.1 over GPT-5.1 Codex High.

    DeepSeek-V3.1 vs GPT-5.1 Codex High comparison

    Token pricing, specs, and benchmarks side by side

    Metric
    DeepSeek-V3.1
    GPT-5.1 Codex High
    Provider
    Provider
    DeepSeek
    OpenAI
    License
    Open Source
    Proprietary
    Release Date
    2025-01-10
    2025-11-12
    Pricing (per 1M tokens)
    Input Price-78%
    $0.27
    $1.25
    Output Price-90%
    $1.00
    $10.00
    Blended (1M + 1M)
    $1.27
    $11.25
    Model Details
    Context Window
    163.8K
    400K
    Max Output Tokens
    163.8K
    128K
    Knowledge Cutoff
    N/A
    N/A
    Throughput
    N/A
    50 tok/s
    Benchmarks
    15.9%
    74.9%
    93.4%
    49.8%
    96.7%
    66.3%
    69.7%
    33.5%
    83.7%
    91.8%
    Benchmark Wins
    DeepSeek-V3.1 0|1 GPT-5.1 Codex High

    Verdict

    DeepSeek-V3.1 vs GPT-5.1 Codex High: the bottom line

    DeepSeek-V3.1 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.

    DeepSeek-V3.1 vs GPT-5.1 Codex High FAQ

    Which is cheaper, DeepSeek-V3.1 or GPT-5.1 Codex High?

    As of August 20, 2026, DeepSeek-V3.1 is 89% cheaper on blended LLM API pricing. DeepSeek-V3.1 costs $0.27 per million input tokens and $1.00 per million output tokens ($1.27 blended 1M-in + 1M-out). GPT-5.1 Codex High costs $1.25 / $10.00 per million tokens ($11.25 blended). Sources: https://api-docs.deepseek.com/quick_start/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 DeepSeek-V3.1 vs GPT-5.1 Codex High cost per million tokens?

    DeepSeek-V3.1 DeepSeek API pricing is $0.27 input and $1.00 output per million tokens via DeepSeek. GPT-5.1 Codex High OpenAI API pricing is $1.25 input and $10.00 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, DeepSeek-V3.1 or GPT-5.1 Codex High?

    DeepSeek-V3.1 has a published SWE-bench Verified score of 66%. GPT-5.1 Codex High does not have that eval on this page yet.

    What is the context window for DeepSeek-V3.1 vs GPT-5.1 Codex High?

    DeepSeek-V3.1 supports a 164K token context window, while GPT-5.1 Codex High supports 400K 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, DeepSeek-V3.1 or GPT-5.1 Codex High?

    GPT-5.1 Codex High leads on 1 of 1 shared benchmarks versus DeepSeek-V3.1'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 DeepSeek-V3.1 or GPT-5.1 Codex High better for production use?

    Both DeepSeek-V3.1 and GPT-5.1 Codex High are production API models. For cost-sensitive production traffic, DeepSeek-V3.1 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 DeepSeek-V3.1 and GPT-5.1 Codex High in my app?

    Yes. Call DeepSeek-V3.1 through DeepSeek and GPT-5.1 Codex High 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 DeepSeek-V3.1 vs GPT-5.1 Codex High pricing data?

    List rates are the latest published DeepSeek API pricing and OpenAI API pricing, quoted per million tokens. Official rate sheets: https://api-docs.deepseek.com/quick_start/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 DeepSeek-V3.1 and GPT-5.1 Codex High?

    DeepSeek-V3.1 supports up to 164K output tokens per request, while GPT-5.1 Codex High 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, DeepSeek-V3.1 or GPT-5.1 Codex High?

    GPT-5.1 Codex High has a measured throughput of approximately 50 tokens/second. Throughput data for DeepSeek-V3.1 is not yet available. 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 DeepSeek-V3.1 vs GPT-5.1 Codex High comparison?

    Use the model pickers at the top of this LLM comparison. Search any model in the index and the URL updates. Open DeepSeek-V3.1 or GPT-5.1 Codex High from the sidebar for the single-model API pricing page, or go back to the LLM pricing table to sort by cheapest blended cost.

    DeepSeek-V3.1 vs GPT-5.1 Codex High pricing

    This comparison covers API pricing, context window, throughput, and benchmark scores. DeepSeek-V3.1 costs $0.27/M input and $1.00/M output. GPT-5.1 Codex High costs $1.25/M input and $10.00/M output.

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

    The index

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