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Claude Fable 5.1 vs Claude Fable 5
Of the 3 public leaderboards that rate both, Claude Fable 5.1 scores higher on 2 and Claude Fable 5 on 0, with 1 tied. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, Claude Fable 5.1 is at 91.7 and Claude Fable 5 at 60.4 (out of 100). On each maker's API, Claude Fable 5.1 costs $10 / $50 per 1M tokens (input / output) and Claude Fable 5 $10 / $50.
Scores as published by each board; table composed November 7, 2026.
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Leaderboard by leaderboard
| Board | Claude Fable 5.1 | Claude Fable 5 | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,745.7 | 1,625 | Claude Fable 5.1 |
| SimpleBench AVG@5 % (private set) | 86.6 | 81.9 | Claude Fable 5.1 |
| LLM Stats LLM Stats Score · composite (0-100), their rendered top 15 | 52.8 | 52.8 | tie |
Raw scores are each board's own scale, so compare within a row, not across rows. Full table: the bench index.
For coding
On the ArtificialWatch coding index, Claude Fable 5.1 is at 89.4 (#4 of 45) and Claude Fable 5 at 88.1 (#5). Claude Fable 5.1 scores higher on 1 of the 2 coding boards that rate both and Claude Fable 5 on 1.
| Coding board | Claude Fable 5.1 | Claude Fable 5 |
|---|---|---|
| LMArena · Coding | 1,529.9 | 1,518.7 |
| Vals Vibe Code Bench | 90.3 | 90.4 |
Claude Fable 5.1 at a glance
- Developer
- Anthropic
- Status
- Live since September 1, 2026
- API price
- $10 input / $50 output per 1M tokens · Anthropic, claude-fable-5-1
- Context window
- 1M tokens
Live - sticker price held at $10/$50, but cache reads cut 75% to $0.25 = ~25% cheaper typical, up to ~45% agentic · 1M ctx · effort low-max.
Claude Fable 5.1 is live — the sticker price never moved, and the cache read fell 75%
2026-09-01 · Claude Fable 5.1 shipped today, alongside Claude Mythos 5.1. Our radar detected it at 17:52:22 UTC and confirmed it on the next sweep 60 seconds later.
Fable 5.1's August window has closed — the market now prices September at 78%, and one claim in the leak can't be checked at all
2026-08-20 · A claim going round today says Fable 5.1 is in pre-release testing, targeted at September, and running inside Anthropic's own products under the Fable 5 name. One part of that is checkable, one part is checkable and slipping, and one part is — by construction — invisible to anything we can measure.
Claude Fable 5 at a glance
- Developer
- Anthropic
- Status
- Live since July 1, 2026
- API price
- $10 input / $50 output per 1M tokens · Anthropic, claude-fable-5
- Context window
- 1M tokens
Returned Jul 1.
Claude Fable 5.1 vs Claude Fable 5: quick answers
Which is better, Claude Fable 5.1 or Claude Fable 5?
It depends on what you measure. Of the 3 public leaderboards that rate both, Claude Fable 5.1 scores higher on 2 and Claude Fable 5 on 0, with 1 tied. Claude Fable 5.1's widest lead is on LMArena. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, Claude Fable 5.1 is at 91.7 and Claude Fable 5 at 60.4 (out of 100).
Which is newer, Claude Fable 5.1 or Claude Fable 5?
Claude Fable 5.1. It went live on September 1, 2026, 62 days after Claude Fable 5 (July 1, 2026).
Which is cheaper, Claude Fable 5.1 or Claude Fable 5?
They cost the same per token. On each vendor's own API, Claude Fable 5.1 is $10 input / $50 output per million tokens and Claude Fable 5 is $10 input / $50 output per million tokens. Prices as published in the models.dev catalog, as of 2026-11-07.
Which has the bigger context window, Claude Fable 5.1 or Claude Fable 5?
Neither. Both take 1M tokens.
How do Claude Fable 5.1 and Claude Fable 5 compare for coding?
On the ArtificialWatch coding index, Claude Fable 5.1 is at 89.4 (#4 of 45) and Claude Fable 5 at 88.1 (#5). Claude Fable 5.1 scores higher on 1 of the 2 coding boards that rate both and Claude Fable 5 on 1.
Who makes Claude Fable 5.1 and Claude Fable 5?
Both are from Anthropic.
Where do these numbers come from?
Each score is the leaderboard's own published figure, read by ArtificialWatch (table composed November 7, 2026). Boards measure different things, so raw scores are only comparable within a row.
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