Claude Fable 5.1
FrontierLast verified: September 25, 2026· Anthropic Claude Fable 5.1 pricing
Anthropic’s most capable widely released model, successor to Fable 5 at the same price. Thinking is always on; 1M-token context window.
- Input / 1M
- $10.00
- Output / 1M
- $50.00
- Context
- 1M tokens
- Provider
- Anthropic
Pricing verified September 25, 2026. Prices change frequently. Always confirm against the provider’s official pricing page before relying on these figures for budgeting. Official pricing →
When to choose Claude Fable 5.1
What Claude Fable 5.1 costs in practice
| Scenario | Input / mo | Output / mo | Est. cost / mo |
|---|---|---|---|
| Prototype | 2M | 0.5M | $45 |
| Growing product | 50M | 10M | $1,000 |
| At scale | 500M | 100M | $10,000 |
Plug in your own numbers with the cost calculator.
Where Claude Fable 5.1 fits in a routing setup
Cheaper alternatives to Claude Fable 5.1
The models immediately below Claude Fable 5.1 on blended cost, nearest first. A swap only pays if quality holds on the routes you move — see the LLM cost optimization playbook for how to prove that before you move them.
Frequently asked questions
How much does Claude Fable 5.1 cost?
Claude Fable 5.1 bills $10.00 per million input tokens and $50.00 per million output tokens — $20.00 per million blended at a three-to-one input:output split. A workload of 50M input and 10M output tokens per month works out at about $1,000.
What is Claude Fable 5.1's context window?
Claude Fable 5.1 has a 1M-token context window, of which up to 128K tokens can be the reply. One request that fills the whole window costs about $10.00 at the input rate, before the reply is billed.
Where does Claude Fable 5.1 sit on price?
At $20.00 per million blended — three input tokens for every output token — Claude Fable 5.1 is every one of the other 18 models tracked here is cheaper. Output bills at 5x the input rate, and the nearest cheaper model on this table is Claude Opus 4.8 at $10.00 blended.
Related concepts: context window, model routing, prompt caching, evals.