Pyyan / Compare / Claude Fable 5 vs GPT-6 Astra
Claude Fable 5 vs GPT-6 Astra
2 of 5Language Models · verified 5 Sept 2026
Claude Fable 5Anthropiccurrent
GPT-6 AstraOpenAIcurrent| Specification | Claude Fable 5 | GPT-6 Astra |
|---|---|---|
| Summary | Most capable widely released model, for the hardest reasoning and long-horizon agentic work. | Saturates three of the benchmarks it reports, and ships disabled for enterprise. |
| Context | 1M | 1.05M |
| Input ($/Mtok) | $10 | $10 |
| Output ($/Mtok) | $50 | $50 |
| Licence | Proprietary | Proprietary |
| Max output | 128K | 128K |
| Parameters | — | Not published |
| Released | — | 3 Sep 2026 |
| Model ID | claude-fable-5 | gpt-6-astra |
| Category | Language Models | Language Models |
| Official | Anthropic ↗ | — |
Highlighted rows are where these differ.
Claude Fable 5
- Thinking is always on — the `thinking` param is rejected
- Raw chain of thought is never returned
- Requires 30-day data retention; unavailable under ZDR
Best for the hardest problems.
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.