Claude Fable 5.1 benchmarks, pricing and specs
Claude Fable 5.1 is an Anthropic model released on September 1, 2026 that takes text and image input and produces text. It costs $10 per 1M input tokens and $50 per 1M output tokens and accepts up to 1,000,000 tokens of context. It scores 1501 Elo on Arena Text, #3 of 39 current models (Arena, measured October 8, 2026).
- Per 1M input tokens
- $10
- Per 1M output tokens
- $50
- Context window
- 1M
- Arena Text
- 1501 Elo · #3/39
Data verified October 12, 2026 · Dataset 2026-10-12
Key facts
- Provider
- Anthropic
- Model family
- Claude Fable
- Release date
- September 1, 2026
- Status
- Current
- Access
- API only
- API model id
- Not reported
- Context window
- 1,000,000 tokens
- Max output
- 128,000 tokens
- Input
- text, image
- Output
- text
- Task families
- text, multimodal
- Declared capabilities
- reasoning
Claude Fable 5.1 pricing
It is tied for the most expensive of 37 current text models priced per 1M input tokens.
Independent benchmark results
Scores come from independent evaluators that ran the model themselves, pinned to a dated snapshot. Rank is among current models in the same snapshot. Anthropic's own launch figures are listed under strengths with the publisher named, because they are not measured the same way.
| Benchmark | Score | Rank | Measured | Source |
|---|---|---|---|---|
| Arena Text | 1501 Elo | #3 of 39 | October 8, 2026 | Arena · 2026-10-12 |
| FrontierMath Tiers 1-3 (v2) | 90.2% | #4 of 37 | October 12, 2026 | Epoch AI · 2026-10-12 |
| SimpleQA Verified | 70.8% | #5 of 34 | October 12, 2026 | Epoch AI · 2026-10-12 |
Strengths, cautions and best uses
Strengths
- Anthropic’s highest-capability generally available model, for demanding reasoning and long-horizon agentic work, with a 1M-token context window and 128,000-token maximum output
- Cache reads are priced at 0.025x base input ($0.25 per million) rather than the 0.1x every other Claude model uses, which is the single largest cost lever for agentic loops that replay a large prompt
- Anthropic reports 52.6% on Terminal-Bench-Science 0.1 against 24.7% for Fable 5 and 29.0% for Opus 5
- Adaptive thinking is always on and the API effort default is `high`
Cautions
- 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
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
Alternatives to Claude Fable 5.1
The closest current textmodels by price. The cheapest model that scores as well or better is listed first; failing that, the cheapest one within 3% of the benchmark's scale.
Cheaper, same or higher score
Claude Opus 5.5
- 60% cheaper per 1M input tokens, $4 vs $10
- 6 points higher on Arena Text, 1507 vs 1501
GPT-6 Astra
- Same price per 1M input tokens, $10
- 26 points lower on Arena Text, 1475 vs 1501
- From OpenAI
Claude Mythos 5.1
- Same price per 1M input tokens, $10
GPT-5.5
- 50% cheaper per 1M input tokens, $5 vs $10
- 19 points lower on Arena Text, 1482 vs 1501
- From OpenAI
Compare Claude Fable 5.1 with
Articles about Claude Fable 5.1
- Claude Fable 5.1: Same Price, 75% Cheaper CacheSeptember 2, 2026
Other Claude Fable models
Claude Fable 5.1 FAQ
How much does Claude Fable 5.1 cost?
Claude Fable 5.1 costs $10 per 1M input tokens and $50 per 1M output tokens at the standard tier. It is tied for the most expensive of 37 current text models priced per 1M input tokens. Source: Anthropic, verified October 11, 2026.
What is the context window of Claude Fable 5.1?
Claude Fable 5.1 accepts up to 1,000,000 tokens of context. It can return up to 128,000 tokens in one response. That ranks #24 of 44 current text models by context length.
How does Claude Fable 5.1 score on independent benchmarks?
Claude Fable 5.1 scores 1501 Elo on Arena Text, #3 of 39 current models (Arena, measured October 8, 2026), 90.2% on FrontierMath Tiers 1-3 (v2), #4 of 37 current models (Epoch AI, measured October 12, 2026) and 70.8% on SimpleQA Verified, #5 of 34 current models (Epoch AI, measured October 12, 2026). These are independent evaluations, not Anthropic's own launch figures.
Is Claude Fable 5.1 open source or API only?
Claude Fable 5.1 is available through Anthropic's API only; its weights are not published.
What are the best alternatives to Claude Fable 5.1?
The closest current alternatives by price and measured performance are Claude Opus 5.5 (60% cheaper per 1M input tokens, $4 vs $10), GPT-6 Astra (same price per 1M input tokens, $10), Claude Mythos 5.1 (same price per 1M input tokens, $10) and GPT-5.5 (50% cheaper per 1M input tokens, $5 vs $10).
Sources
- Claude models overview · Anthropic · official · verified October 11, 2026
- Claude API pricing · Anthropic · official · verified October 11, 2026
- Epoch AI Benchmarking Hub data (benchmark_data.zip) · Epoch AI · independent · verified October 12, 2026 · CC-BY-4.0
- Arena leaderboard dataset (lmarena-ai/leaderboard-dataset) · Arena · independent · verified October 12, 2026 · CC-BY-4.0
Cite this page
Van Data Team. "Claude Fable 5.1 Benchmarks, Pricing and Specs." AI Model Benchmark Dataset 2026-10-12. https://vandatateam.com/ai-model-benchmarks/claude-fable-5-1
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Production evaluation
Deciding whether Claude Fable 5.1 fits your workload?
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