Head to head
Claude Fable 5 vs GPT-5.6 Sol
Which is better, Claude Fable 5 or GPT-5.6 Sol?
Claude Fable 5 finishes ahead of GPT-5.6 Sol on the index, 85.6 to 84.4. It is the stronger of the two on Craft, while GPT-5.6 Sol still leads on Value. Both are scored on the same rubric, in the same week, and neither placing is sponsored.
Updated
Claude Fable 5
17 of 73
85.6
Still excellent, but Fable 5.1 replaced it at the same price and Opus 5.5 beats both for less.
GPT-5.6 Sol
25 of 73
84.4
Strong and now discounted, but GPT-6.1 Sol beats it for half the money.
The four scores, side by side
| Score | Claude Fable 5 | GPT-5.6 Sol | Difference |
|---|---|---|---|
| Craft | 93 | 89 | +4 |
| Speed | 76 | 74 | +2 |
| Control | 91 | 91 | — |
| Value | 66 | 72 | +6 |
| Index score | 85.6 | 84.4 | +1.2 |
Which to pick
Pick Claude Fable 5 unless Value is what decides it for you, which is exactly where GPT-5.6 Sol is the better answer.
Claude Fable 5
Fable 5 was the top of this index in the summer and it remains a very strong model for long autonomous runs. It is now a legacy model: Fable 5.1 costs the same with better results and cheaper cached input, and Opus 5.5 outscores both at well under half the price. Anthropic will keep serving it until at least June 2027, so existing work does not need to move in a hurry. New work should start somewhere else.
Where it shines
- Holds a long, messy task together for hours without drifting
- Refuses cleanly and explains itself rather than inventing an answer
- Supported until at least June 2027
GPT-5.6 Sol
GPT-5.6 Sol was OpenAI's deepest thinker in the summer and remains strong on mathematics and long reasoning. OpenAI has cut its price to four dollars in and twenty out until at least late November, but GPT-6.1 Sol now costs half that with better scores, and ChatGPT has already moved to GPT-6. It is still active on the API, which matters for anyone whose prompts were tuned against it.
Where it shines
- Still strong on mathematics and formal reasoning
- Context window past a million tokens
- Temporarily discounted from its launch price