Claude Fable 5.1 vs GPT-6 Astra
Claude Fable 5.1 vs GPT-6 Astra: which AI model is cheaper, has the larger context window and more capabilities? Side-by-side comparison updated daily.
Quick verdict
- Both models cost about the same.
- GPT-6 Astra has the larger context window (1.1M), useful for long documents and big codebases.
- GPT-6 Astra is the more recent release (Sep 4, 2026).
- GPT-6 Astra scores higher on independent tests (overall index 166.6 vs 165.0).
| Claude Fable 5.1 | GPT-6 Astra | |
|---|---|---|
| Company | Anthropic | OpenAI |
| Released | Sep 1, 2026 | Sep 4, 2026 ● |
| Overall index | 165.0 | 166.6 ● |
| GPQA Diamond | — | 95.8% |
| AIME math | 100% | 100% |
| FrontierMath | 90.2% | 93.7% ● |
| SimpleQA Verified | 70.8% | 75.6% ● |
| Input (per 1M tokens) | $10 | $10 |
| Output (per 1M tokens) | $50 | $50 |
| Cost for 1M input + 1M output tokens | $60.00 | $60.00 |
| Providers | 4 | 7 ● |
| Context | 1M | 1.1M ● |
| Max output | 128K | 128K |
| Inputs | Text, Image, Files | Files, Image, Text |
| Outputs | Text | Text |
| Reasoning | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Open weights | — | — |