Pyyan / Compare / GPT-6 Luna vs Claude Fable 5
GPT-6 Luna vs Claude Fable 5
2 of 5Language Models · verified 24 Sept 2026
GPT-6 LunaOpenAIcurrentClaude Fable 5Anthropiccurrent
| Specification | GPT-6 Luna | Claude Fable 5 |
|---|---|---|
| Summary | Ten cents a million in, for the work that does not need thinking. | Most capable widely released model, for the hardest reasoning and long-horizon agentic work. |
| Context | 1.05M | 1M |
| Input ($/Mtok) | $0.1 | $10 |
| Output ($/Mtok) | $0.5 | $50 |
| Licence | Proprietary | Proprietary |
| Max output | 128K | 128K |
| Parameters | Not published | — |
| Released | 22 Sep 2026 | — |
| Model ID | gpt-6-luna | claude-fable-5 |
| Category | Language Models | Language Models |
| Official | OpenAI ↗ | Anthropic ↗ |
Highlighted rows are where these differ.
GPT-6 Luna
- Half the price of GPT-5.6 Luna, which it replaces at the bottom of the family
- Beats or matches GPT-5.6 Luna on all five benchmarks OpenAI published
- Same 1.05M context window as the tiers above it
Best for classification and high-volume chat.
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.