Claude Fable 5.1
The reach-for-it model when Opus 5 at high effort still fails your evals: hardest reasoning and multi-hour agentic runs.
Data checked 2026-09-06
Anthropic
ga
claude-fable-5-1
- Context window
- 1M tokens in
- Max output
- 128K tokens out
- Input
- $10.00 per 1M tokens
- Output
- $50.00 per 1M tokens
- Cached input
- $0.25 per 1M tokens
- Blended
- $20.00 3:1 in:out
- Knowledge cutoff
- 2026-06
- Released
- 2026-09-01
- Licence
- proprietary
A What it is for
Thinking is always on, forced tool_choice returns 400, and cache reads are 2.5% of input ($0.25/MTok) - the cheapest cache in the lineup, so it pays off hardest on long stateful agents.
At a three-to-one input-to-output ratio, Claude Fable 5.1 costs $20.00 per million tokens blended. A workload of one million input and 330,000 output tokens per day would run about $795.00 per month at list price, before caching or batch discounts.
B Capabilities
| Input modalities | text, image, pdf |
|---|---|
| Output modalities | text |
| Batch discount | 50% off asynchronous requests |
C Others from Anthropic
| Model | Context | Max out | In $/M | Out $/M | Blended | Status |
|---|---|---|---|---|---|---|
Claude Mythos 5.1
claude-mythos-5-1
|
1M | 128K | $10.00 | $50.00 | $20.00 | preview |
Claude Fable 5
claude-fable-5
|
1M | 128K | $10.00 | $50.00 | $20.00 | ga |
Claude Mythos 5
claude-mythos-5
|
1M | 128K | $10.00 | $50.00 | $20.00 | preview |
Claude Opus 5
claude-opus-5
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.8
claude-opus-4-8
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.7
claude-opus-4-7
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.6
claude-opus-4-6
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.5
claude-opus-4-5-20251101
|
200K | 64K | $5.00 | $25.00 | $10.00 | ga |
Claude Sonnet 5
claude-sonnet-5
|
1M | 128K | $2.00 | $10.00 | $4.00 | ga |
Claude Sonnet 4.6
claude-sonnet-4-6
|
1M | 128K | $3.00 | $15.00 | $6.00 | ga |
Claude Sonnet 4.5
claude-sonnet-4-5-20250929
|
200K | 64K | $3.00 | $15.00 | $6.00 | ga |
Claude Haiku 4.5
claude-haiku-4-5-20251001
|
200K | 64K | $1.00 | $5.00 | $2.00 | ga |
D Verify before you commit
Model pricing changes without notice and this page is a snapshot. Confirm against the vendor's own page before you build a budget on it.
Source: platform.claude.com · checked 2026-09-06 · Anthropic pricing · API docs