text model comparison
Claude Fable 5 vs Claude Fable 5.1
Claude Fable 5 and Claude Fable 5.1 are both current text models, from Anthropic. Both cost $10 per 1M input tokens. On Arena Text, Claude Fable 5 scores 1504 Elo and Claude Fable 5.1 1501 Elo (Arena, measured October 8, 2026). Both accept 1,000,000 tokens of context.
Data verified October 12, 2026 · Dataset 2026-10-12
Side by side
Standard-tier prices in effect today. The better value in each row is highlighted.
| Fact | Claude Fable 5 | Claude Fable 5.1 |
|---|---|---|
| Price per 1M input tokens | $10 | $10 |
| Price per 1M output tokens | $50 | $50 |
| Cost of 10M input and 2M output tokens | $200 | $200 |
| Arena Text | 1504 Elo (#2 of 39) (better) | 1501 Elo (#3 of 39) |
| FrontierMath Tiers 1-3 (v2) | 87% (#8 of 37) | 90.2% (#4 of 37) (better) |
| SimpleQA Verified | 70.7% (#6 of 34) | 70.8% (#5 of 34) (better) |
| GPQA Diamond | 85.9% (#30 of 37) | Not measured |
| Provider | Anthropic | Anthropic |
| Release date | June 9, 2026 | September 1, 2026 |
| Access | API only | API only |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Input | text, image | text, image |
| Output | text | text |
When to choose each
Claude Fable 5
Best for
- Long-horizon coding, reasoning, and knowledge-work evaluations
Watch out for
- Fable requires 30-day data retention, and classifier-triggered requests fall back to Claude Opus 4.8
Claude Fable 5.1
Best for
- Long-horizon agentic coding where a large prompt prefix is replayed across many turns
- Work where Claude Opus 5 at higher effort has already been evaluated and fell short
Watch out for
- Base input and output pricing is unchanged from Fable 5 at $10 / $50; the saving is entirely in cache reads, so a workload with little cache reuse sees no discount
- The 4.7-generation tokenizer produces roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier, so per-token rates are not directly comparable across generations
- Anthropic’s launch comparisons are self-reported and were not reproduced independently here
Claude Fable 5 vs Claude Fable 5.1 FAQ
Which is cheaper, Claude Fable 5 or Claude Fable 5.1?
Both cost $10 per 1M input tokens. For 10M input and 2M output tokens, Claude Fable 5 costs $200 and Claude Fable 5.1 $200 at standard rates.
Which scores higher on independent benchmarks, Claude Fable 5 or Claude Fable 5.1?
Claude Fable 5 leads on Arena Text, 1504 Elo to 1501 Elo; Claude Fable 5.1 leads on FrontierMath Tiers 1-3 (v2), 90.2% to 87%; Claude Fable 5.1 leads on SimpleQA Verified, 70.8% to 70.7%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Fable 5 or Claude Fable 5.1?
Both accept 1,000,000 tokens of context.
Related comparisons
Production evaluation
Choosing between Claude Fable 5 and Claude Fable 5.1?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty