Claude Fable 5.1 pricing at a glance
- Provider: Anthropic
- Input: $10.00 per million tokens
- Output: $50.00 per million tokens
- Cached input: $0.25 per million tokens
- Context window: 1,000,000 tokens
- Prices verified: September 24, 2026
About Claude Fable 5.1
Fable 5.1 is the most expensive Claude model in the public price list, at $10 per million input tokens and $50 per million output. Its cache-read price is unusually low — 2.5% of the base input rate, or $0.25 per million — so a large, stable prompt that is reused across many calls costs far less than the headline rate suggests. Anthropic notes that Claude 4.7 and later models use a newer tokenizer that produces roughly 30% more tokens for the same text than earlier Claude models, so a prompt counted here with a generic encoding is likely to be billed higher on this model.
What Claude Fable 5.1 costs in practice
A call with 1,000 input tokens and 500 output tokens costs $0.035 on Claude Fable 5.1, so a thousand such calls cost $35.00. With prompt caching, a cache read is priced at $0.25 per million tokens, 98% below the standard input rate. Its 1M-token context window holds roughly 750,000 English words, or about 1,500 pages at 500 words a page; filling all of it once costs $10.00 in input tokens.
How this Claude Fable 5.1 token counter counts tokens
Claude Fable 5.1’s own tokenizer cannot be run in a browser, so this page counts with OpenAI’s o200k_base encoding and marks the result ≈. Use it to size a prompt and compare costs, then confirm against the usage figures the API returns.
How to use it
- Paste your prompt into the box, or drop a .txt or .md file on it.
- Set the expected output length and how many calls you make per day.
- Compare the cost per call and per month across models; the cheapest is highlighted.
- Tick the cache option if your prompt prefix is reused, then copy the table if you need it elsewhere.
Frequently asked questions
How many tokens is my text in Claude Fable 5.1?
Paste it into the box above. The number shown for this model is an estimate made with o200k_base and marked ≈, so the API’s own count can differ.
How much does Claude Fable 5.1 cost per million tokens?
$10.00 per million input tokens and $50.00 per million output tokens, with cached input at $0.25, as of September 24, 2026.
Is my prompt sent to a server?
No. Counting runs in a background thread in your browser. The site records only an anonymous counter such as how many models were compared, never the text you paste.
Prices verified September 24, 2026 from Anthropic’s pricing page. Confirm on the provider’s site before budgeting.