MODEL PROOF
Claude Fable 5.1
FRONTIER
Nothing is both better and cheaper under this workload.
- Independent LMArena score
- 1,507.6 ± 8.15 · 5,783 votes
- Context window
- 1M
- Maximum output
- 128K
- Input modalities
- text, image, file
- Output modalities
- text
- Published input price
- $10.00 / 1M tokens
- Published output price
- $50.00 / 1M tokens
- Pricing kind
- fixed
MODEL MONUMENT
Save or share this proof
Anthropic: Claude Fable 5.1. Balanced workload. Frontier. Evidence as of 19 Sept 2026.
$10.00/M in, $50.00/M out in this catalogue, as of the fetch date on this page. That is the API row, not a subscription. Nothing is both better and cheaper than Claude Fable 5.1.
Every price dimension
| Input | $10.00/M |
|---|---|
| Output | $50.00/M |
| Cached input | $0.250/M |
| Cache write | $12.50/M |
| Cache write 1h | $20.00/M |
| Web search | $0.01/call |
Who sells it
The same weights, different shops. Cheapest is not like-for-like when serving precision differs.
| Seller | Input | Output | Precision | Uptime (1d) |
|---|---|---|---|---|
| Azure | $10.00 | $50.00 | undeclared | 99.79% |
| Anthropic | $10.00 | $50.00 | undeclared | 99.84% |
| Amazon Bedrock | $10.00 | $50.00 | undeclared | — |
| $10.00 | $50.00 | undeclared | 99.75% |
Independent scores
| LMArena Elo | 1507.6max |
|---|
LMArena Elo under CC BY 4.0. Absence of another board is not a score of zero.
Best rankings by task
- dataviz #1of 106 1368
- svg #1of 77 1347
- fullstack #1of 41 1336
- webapps #1of 39 1336
- python-pptxslides #1of 26 1328
- gamedev #2of 107 1402
- website #3of 114 1322
- codecategories #3of 108 1346
Capability
| Context window | 1M |
|---|---|
| Max output | 128K |
| Input modes | text, image, file |
| Tool use | yes |
| Reasoning | always on |
Provenance
| Price source | openrouter.ai |
|---|---|
| Fetched | 2026-09-19 |
| Quality data | verified |
Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual...
Questions this page answers
What does Claude Fable 5.1 cost?
$10.00/M in, $50.00/M out in this catalogue, as of the fetch date on this page. That is the API row, not a subscription.
Does Claude Fable 5.1 have an independent quality score?
Claude Fable 5.1 has an LMArena score in this catalogue.
What beats Claude Fable 5.1?
Nothing is both better and cheaper than Claude Fable 5.1.
Does this page use Artificial Analysis scores for Claude Fable 5.1?
No. Artificial Analysis figures are not published here. Quality on this page is LMArena Elo where a score exists; otherwise the row is unrated.
Check whether this is still the one to buy
Badge
The verdict as one SVG, for a README or a docs page. It states this model's dominance status at the balanced workload on the LMArena lens, with the date it was computed, and it is rebuilt with the catalogue — so it changes when the verdict changes, including to one you would rather it did not.
[](https://undominated.ai/models/anthropic__claude-fable-5.1/)<a href="https://undominated.ai/models/anthropic__claude-fable-5.1/"><img src="https://undominated.ai/badge/anthropic__claude-fable-5.1.svg" alt="Claude Fable 5.1 — Undominated.ai dominance verdict" height="36"></a>Direct file: https://undominated.ai/badge/anthropic__claude-fable-5.1.svg — a static SVG, written by scripts/build-badges.mjs on every build, so the copy you embed is never
older than the last deploy.
