Claude Mythos 5.1
AnthropicProprietaryReasoningReleased Sep 1, 2026
Overall score
—
Not enough evidence to rank yet
Context window
1M
1,000,000 tokens
Price per 1M tokens
$10.00 in · $50.00 out
✓ Verified on Anthropic's pricing page
Blended price
$20.00
3:1 input:output tokens
Output speed
—
Not measured yet
Benchmark results (1)
As reported in system cards, papers and public evaluations. Position compares this model with every other model reporting the same benchmark.
Agentic & tool use
| Terminal-Bench 4.0 | 60.90 | #3 of 18 |
Pricing by source
USD per 1M tokens.
| Source | Input | Output | Cached in |
|---|---|---|---|
| ✓ Official (Anthropic) checked Oct 17, 2026 · Claude Mythos 5.1 | $10.00 | $50.00 | $0.25 |
| BenchLM list price | $10.00 | $50.00 | $0.25 |
Limited availability.
Anthropic limits Claude Mythos 5.1 to vetted cyberdefenders and life scientists through trusted access programs. The launch page does not publish a separate generally available token-price row or callable public API ID for this restricted profile, so pricing remains unresolved rather than inheriting Fable 5.1's rate.
Speed
Measured by us through OpenRouter (median of trials).
Not available on OpenRouter, so we cannot measure it yet.