Claude Fable 5 vs Claude Sonnet 4.5
Head to head on 24 shared benchmarks, with price, context window, and release dates.
Benchmark scores
98evals · sort by any column, ⤢ to expand fullscreen
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| Claude Fable 5 Anthropic | 71.8% | 1933elo | 83 | 92.6% | 55.5% | 63.5% | 81.4% | 78.6% | 80.0% | 59.9% | 88.5% | 93.9% | 87.3% | 56.1% | 88.5% | 68.9% | 85.0% | 95.0% | 51.9% | 60.2% | 76.9% | 62.9% | 90.4% | 98.5% | - | - | - | - | - | - | - | 17.4% | - | 83.9% | 38.6% | - | - | - | 90.0% | - | - | 1340elo | 78.0% | - | - | 56.3% | 29.3% | - | - | 29.8% | 1932elo | - | - | - | - | - | 66.0% | - | - | - | - | 13.3% | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 80.3% | - | - | - | - | 88.0% | - | 66.0% | 74.2% | - | - | 69.4% |
| Claude Sonnet 4.5 Anthropic | 60.8% | 1675elo | 71.4 | 72.7% | 7.2% | 42.7% | 70.7% | 80.4% | 57.0% | 53.4% | 76.5% | 79.3% | 77.6% | 40.6% | 84.5% | 64.0% | 62.9% | 19.0% | 32.9% | 42.8% | 73.3% | 28.8% | 22.6% | 70.5% | 0.0% | 0.0% | 37.0% | 100 | 0.0% | 0.0% | 0.0% | - | 5.0% | - | - | 0.0% | 0.0% | 0.0% | - | 0.0% | 0.0% | - | - | 0.0% | 0.0% | - | - | 15.2% | 0.0% | - | - | 0.0% | 83.9% | 0.0% | 0.0% | 0.0% | - | 0.0% | 0.0% | 87.5% | 83.8% | - | 0.0% | 0.0% | 59.0% | 0.75 | 0.75 | 0.0% | 0 | 0 | 86.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0 | 0.0% | 0.0% | 77.2% | 67.0% | 74.8% | - | 0.0% | 0 | 0 | 50.34 | - | 0 | - | - | 0.0% | 1.49 | 27.5% |
2 / 2 models
| Attribute | Claude Fable 5 Anthropic | Claude Sonnet 4.5 Anthropic |
|---|---|---|
| Description | Claude Fable 5 is Anthropic's most capable widely released model, built for the most demanding reasoning and long-horizon agentic work. Shares its base model with the invitation-only Claude Mythos 5. | anthropic/claude-sonnet-4.5 is an AI model. |
| Family | Claude | Claude |
| Params | - | Undisclosed (closed) |
| Open weights | closed | closed |
| License | - | Proprietary |
| Released | 9 Jun 2026 | 29 Sep 2025 |
| Context | 1,000,000 | 1,000,000 |
| Input $/1M | $10.00 | $3.00 |
| Output $/1M | $50.00 | $15.00 |
| Cache read $/1M | $1.000 | $0.300 |
| Cache write $/1M | $12.500 | $3.750 |
| Speed | 66 tok/s | 0 tok/s |
| Latency | 49.62 s | 0.00 s |
| Modalities | text, image, file | text, image, file |
| Providers | - | anthropic, aws-bedrock, vertex-ai |
| Publisher | Anthropic | Anthropic |
| Reported scores | Finance Agent (v2)56.3% IFBench63.5% (AA) Swebenchpro80.3% LiveBench - Math93.9% (LiveBench) LiveBench - Coding78.6% (LiveBench) | TaxEval v273.3% LiveBench - Math79.3% (LiveBench) LiveBench - Coding80.4% (LiveBench) LiveBench - Language76.5% (LiveBench) LiveBench - Data Analysis57.0% (LiveBench) |
FAQ
- Is Claude Fable 5 or Claude Sonnet 4.5 better?
- Across the 24 benchmarks both models report on Sophon, Claude Fable 5 leads on 23 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
- How do Claude Fable 5 and Claude Sonnet 4.5 compare on GPQA Diamond?
- Claude Fable 5 scores 92.6% and Claude Sonnet 4.5 scores 72.7% on GPQA Diamond.
- Which is cheaper, Claude Fable 5 or Claude Sonnet 4.5?
- Claude Sonnet 4.5 is cheaper at $15.00 per million output tokens against $50.00 for Claude Fable 5 - about 3.3x.
- When were Claude Fable 5 and Claude Sonnet 4.5 released?
- Claude Fable 5 was released 9 Jun 2026 by Anthropic. Claude Sonnet 4.5 was released 29 Sep 2025 by Anthropic.
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