Claude Mythos 5.1 pricing
Anthropic · list prices as of 2026-09-29
| Input | $10 per 1M tokens |
|---|---|
| Output | $50 per 1M tokens |
| Cached input (read) | $0.25 per 1M tokens |
| Cache write | $12.50 per 1M tokens |
| Batch / async | 50% off |
| Context window | 1M tokens |
| Longest answer | 128K tokens |
What a call costs
| Typical call | Input tokens | Output tokens | Per call | Per month at 1,000 a day |
|---|---|---|---|---|
| Chat reply | 1,000 | 300 | $0.0250 | $750.00 |
| Document summary | 6,000 | 400 | $0.0800 | $2,400 |
| Code change | 3,000 | 1,200 | $0.0900 | $2,700 |
No caching or batch discount. Your own prompt will differ: count it exactly below.
Price your own prompt on Claude Mythos 5.1Similarly priced models
- Claude Fable 5 (Anthropic): about the same
- Claude Fable 5.1 (Anthropic): about the same
- Claude Mythos 5 (Anthropic): about the same
- GPT-4 Turbo (OpenAI): 1.3× cheaper
- o1 (OpenAI): 1.3× more
Questions
How much does Claude Mythos 5.1 cost?
Claude Mythos 5.1 costs $10 per million input tokens and $50 per million output tokens, as of 2026-09-29.
How much is one Claude Mythos 5.1 call?
A call with 1,000 input tokens and a 300-token answer costs about $0.0250, or $750.00 a month at 1,000 calls a day.
How big is the Claude Mythos 5.1 context window?
1,000,000 tokens.