Claude Mythos Preview vs GPT-5 Medium

    Comparison

    As of August 20, 2026, GPT-5 Medium is 81% cheaper per million tokens than Claude Mythos Preview. Claude Mythos Preview is $10.00 / $50.00 per million input/output tokens versus GPT-5 Medium at $1.25 / $10.00. Sources: https://platform.claude.com/docs/en/about-claude/pricing and https://developers.openai.com/api/docs/pricing

    Sources: Anthropic Claude API pricing (https://platform.claude.com/docs/en/about-claude/pricing); OpenAI API pricing (https://developers.openai.com/api/docs/pricing)

    Claude Mythos Preview

    Anthropic

    $60.00blended / 1M

    Input

    $10.00

    Output

    $50.00

    1M ctx|Proprietary
    81%
    cheaper
    Better value

    GPT-5 Medium

    OpenAI

    $11.25blended / 1M

    Input

    $1.25

    Output

    $10.00

    400K ctx|Proprietary
    Save $48.75 per million tokens by choosing GPT-5 Medium over Claude Mythos Preview.

    Claude Mythos Preview vs GPT-5 Medium comparison

    Token pricing, specs, and benchmarks side by side

    Metric
    Claude Mythos Preview
    GPT-5 Medium
    Provider
    Provider
    Anthropic
    OpenAI
    License
    Proprietary
    Proprietary
    Release Date
    N/A
    2025-08-07
    Pricing (per 1M tokens)
    Input Price+700%
    $10.00
    $1.25
    Output Price+400%
    $50.00
    $10.00
    Blended (1M + 1M)
    $60.00
    $11.25
    Model Details
    Context Window
    1M
    400K
    Max Output Tokens
    N/A
    128K
    Knowledge Cutoff
    2026-01
    2024-09-30
    Throughput
    N/A
    90 tok/s
    Benchmark Wins
    Claude Mythos Preview 1|0 GPT-5 Medium

    Verdict

    Claude Mythos Preview vs GPT-5 Medium: the bottom line

    GPT-5 Medium offers significantly lower pricing, while Claude Mythos Preview leads on benchmark performance. Your choice depends on whether cost efficiency or raw capability matters more for your use case.

    Claude Mythos Preview vs GPT-5 Medium FAQ

    Which is cheaper, Claude Mythos Preview or GPT-5 Medium?

    As of August 20, 2026, GPT-5 Medium is 81% cheaper on blended LLM API pricing. GPT-5 Medium costs $1.25 per million input tokens and $10.00 per million output tokens ($11.25 blended 1M-in + 1M-out). Claude Mythos Preview costs $10.00 / $50.00 per million tokens ($60.00 blended). Sources: https://platform.claude.com/docs/en/about-claude/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 Claude Mythos Preview vs GPT-5 Medium cost per million tokens?

    Claude Mythos Preview Claude API pricing from Anthropic is $10.00 input and $50.00 output per million tokens via Anthropic. GPT-5 Medium 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, Claude Mythos Preview or GPT-5 Medium?

    Claude Mythos Preview has a published SWE-bench Verified score of 93.9%. GPT-5 Medium does not have that eval on this page yet.

    What is the context window for Claude Mythos Preview vs GPT-5 Medium?

    Claude Mythos Preview supports a 1M token context window, while GPT-5 Medium supports 400K tokens. Claude Mythos Preview 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, Claude Mythos Preview or GPT-5 Medium?

    Claude Mythos Preview leads on 1 of 1 shared benchmarks versus GPT-5 Medium'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 Claude Mythos Preview or GPT-5 Medium better for production use?

    Both Claude Mythos Preview and GPT-5 Medium are production API models. For cost-sensitive production traffic, GPT-5 Medium 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 Claude Mythos Preview and GPT-5 Medium in my app?

    Yes. Call Claude Mythos Preview through Anthropic and GPT-5 Medium 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 Claude Mythos Preview vs GPT-5 Medium pricing data?

    List rates are the latest published Claude API pricing from Anthropic and OpenAI API pricing, quoted per million tokens. Official rate sheets: https://platform.claude.com/docs/en/about-claude/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 Claude Mythos Preview and GPT-5 Medium?

    Claude Mythos Preview supports up to an unspecified number of output tokens per request, while GPT-5 Medium 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, Claude Mythos Preview or GPT-5 Medium?

    GPT-5 Medium has a measured throughput of approximately 90 tokens/second. Throughput data for Claude Mythos Preview 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 Claude Mythos Preview vs GPT-5 Medium comparison?

    Use the model pickers at the top of this LLM comparison. Search any model in the index and the URL updates. Open Claude Mythos Preview or GPT-5 Medium from the sidebar for the single-model API pricing page, or go back to the LLM pricing table to sort by cheapest blended cost.

    Claude Mythos Preview vs GPT-5 Medium pricing

    This comparison covers API pricing, context window, throughput, and benchmark scores. Claude Mythos Preview costs $10.00/M input and $50.00/M output. GPT-5 Medium costs $1.25/M input and $10.00/M output.

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

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