Pyyan / Compare / GPT-6 Astra vs Claude Fable 5.1
GPT-6 Astra vs Claude Fable 5.1
2 of 5Language Models · verified 5 Sept 2026
GPT-6 AstraOpenAIcurrentClaude Fable 5.1Anthropiccurrent
| Specification | GPT-6 Astra | Claude Fable 5.1 |
|---|---|---|
| Summary | Saturates three of the benchmarks it reports, and ships disabled for enterprise. | Same price as Fable 5, and cache reads cost a quarter of what they did. |
| Context | 1.05M | 1M |
| Input ($/Mtok) | $10 | $10 |
| Output ($/Mtok) | $50 | $50 |
| Licence | Proprietary | Proprietary |
| Max output | 128K | 128K |
| Parameters | Not published | Not published |
| Released | 3 Sep 2026 | 1 Sep 2026 |
| Model ID | gpt-6-astra | claude-fable-5-1 |
| Category | Language Models | Language Models |
| Official | — | — |
Highlighted rows are where these differ.
GPT-6 Astra
- 97.6% on FrontierMath Tier 4, 99.9% on ARC-AGI-3 and 100% on ExploitBench
- Above 272K input tokens the whole request reprices: input and cache at 2x, output at 1.5x
- Rolls out to OpenAI's Daybreak cyber programme first, and arrives switched off for enterprise
Best for hard reasoning and computer use.
Claude Fable 5.1
- Matches or beats Fable 5 at low and medium effort, and pulls clear at high effort
- Cache reads cut to 25% of the old price, so re-reading a long context got much cheaper
- Identical model to Mythos 5.1 underneath; the difference is the safeguards
Best for coding and long-running work.