Claude Fable 5.1
Anthropic · released 1 Sep 2026 · proprietary API
- 1M context
- Text + image in
Anthropic's most capable model; demanding reasoning and long-horizon agentic work.
Context window
1M
1,000,000 tokens
Input price
$10
per 1M tokens
Output price
$50
per 1M tokens
Blended
$20
3:1 in:out mix
Weights
Proprietary
API only
Released
1 Sep 2026
Anthropic
Long-context / tier pricing — Cache reads are $0.25/1M, 0.025x base input, against 0.1x on every other Claude. Uses the post-4.7 tokenizer, about 30% more tokens for the same text. Listed prices are the base rate for prompts up to ~200K tokens.
Where it ranks
Of 25 models tracked.
Cost to run
#24(tied)
of 25
Input price
#24(tied)
of 25
Context window
#5(tied)
of 25
Compare with
The nearest models by blended cost to run.
Put it to work
Specs from BitByteCore's hand-verified Frontier Ledger (v2026-09-03), this row verified 3 Sep 2026 against Anthropic's official pricing ↗. Model pricing moves fast, so confirm with Anthropic before you rely on a figure.