According to UsagePricing's tracker, Claude Mythos 5.1 costs $10.00 per 1M input tokens and $50.00 per 1M output tokens as of September 2026. The model supports a 1,000,000-token context window.
Same model and rate card as Fable 5.1, restricted to vetted organisations. Launched Sep 1, 2026 — 1M context, 128K max output.
Token Costs (per 1M)
Technical Specs
Price History
| Date | Input Price | Output Price |
|---|---|---|
| 9/1/2026 | $10.00 | $50.00 |
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Frequently Asked Questions
How much does Claude Mythos 5.1 cost per 1M tokens? ▼
Claude Mythos 5.1 costs $10 per 1M input tokens and $50 per 1M output tokens as of September 2026.
What is Claude Mythos 5.1's context window? ▼
Claude Mythos 5.1 has a context window of 1,000,000 tokens, meaning it can process approximately 750,000 words in a single request.
Who makes Claude Mythos 5.1? ▼
Claude Mythos 5.1 is made by Anthropic. You can access it via the Anthropic API.