Claude Fable 5 vs GPT-5 Nano
Head to head on 21 shared benchmarks, with price, context window, and release dates.
Benchmark scores
68evals · sort by any column, ⤢ to expand fullscreen
| Model | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Fable 5 Anthropic | 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% | 95.0% | 51.9% | 60.2% | 76.9% | 62.9% | 98.5% | - | - | 17.4% | - | 83.9% | - | 38.6% | - | 71.8% | 90.0% | - | 1340elo | 78.0% | 56.3% | - | 29.3% | - | - | 29.8% | 1932elo | - | 66.0% | 13.3% | - | - | - | - | - | - | - | - | - | 85.0% | - | - | - | 80.3% | 88.0% | - | 66.0% | 74.2% | - | - | 90.4% | - | - | - | 69.4% |
| GPT-5 Nano OpenAI | 703elo | 28 | 42.8% | 4.0% | 32.5% | 52.8% | 62.4% | 43.4% | 55.7% | 46.8% | 68.4% | 40.3% | 30.4% | 72.9% | 53.6% | 12.0% | 30.4% | 29.1% | 67.4% | 6.8% | 25.7% | 0.0% | 27.3% | - | 0.25 | - | 0.21 | - | 6.7% | - | - | 10.0% | - | - | - | 78.2% | - | 8.3% | 1.18 | - | - | 100.0% | - | - | 47.0% | 1.38 | 1.38 | 100.0% | 100.0% | 26.7% | 55.6% | 100.0% | 0.0% | - | 0.0% | 1.72 | 34.8% | - | - | 29.7% | - | - | 20.41 | -6.67 | - | 82.0% | 82.0% | 40.0% | 43.7% |
2 / 2 models
| Attribute | Claude Fable 5 Anthropic | GPT-5 Nano OpenAI |
|---|---|---|
| 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. | GPT-5 nano is an AI model from OpenAI. |
| Family | Claude | GPT |
| Params | - | - |
| Open weights | closed | closed |
| License | - | proprietary |
| Released | 9 Jun 2026 | 7 Aug 2025 |
| Context | 1,000,000 | 400,000 |
| Input $/1M | $10.00 | $0.05 |
| Output $/1M | $50.00 | $0.40 |
| Cache read $/1M | $1.000 | $0.005 |
| Cache write $/1M | $12.500 | - |
| Speed | 66 tok/s | 0 tok/s |
| Latency | 49.62 s | 0.00 s |
| Modalities | text, image, file | text, image, file |
| Providers | - | - |
| Publisher | Anthropic | OpenAI |
| Reported scores | Finance Agent (v2)56.3% IFBench63.5% (AA) Swebenchpro80.3% LiveBench - Math93.9% (LiveBench) LiveBench - Coding78.6% (LiveBench) |
FAQ
- Is Claude Fable 5 or GPT-5 Nano better?
- Across the 21 benchmarks both models report on Sophon, Claude Fable 5 leads on 21 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
- How do Claude Fable 5 and GPT-5 Nano compare on GPQA Diamond?
- Claude Fable 5 scores 92.6% and GPT-5 Nano scores 42.8% on GPQA Diamond.
- Which is cheaper, Claude Fable 5 or GPT-5 Nano?
- GPT-5 Nano is cheaper at $0.40 per million output tokens against $50.00 for Claude Fable 5 - about 125.0x.
- When were Claude Fable 5 and GPT-5 Nano released?
- Claude Fable 5 was released 9 Jun 2026 by Anthropic. GPT-5 Nano was released 7 Aug 2025 by OpenAI.
Comparing something else? Build your own side-by-side.