Head to head
Claude Opus 5 vs GPT-5.6 Sol
Which is better, Claude Opus 5 or GPT-5.6 Sol?
GPT-5.6 Sol finishes ahead of Claude Opus 5 on the index, 88.6 to 88.5. It is the stronger of the two on Craft, while Claude Opus 5 still leads on Speed and Value. Both are scored on the same rubric, in the same week, and neither placing is sponsored.
Updated
Claude Opus 5
03 of 53
88.5
Most of the flagship, at half the price. The one to reach for by default.
GPT-5.6 Sol
02 of 53
88.6
OpenAI's deepest thinker: the one to hand a problem you cannot solve yourself.
The four scores, side by side
| Score | Claude Opus 5 | GPT-5.6 Sol | Difference |
|---|---|---|---|
| Craft | 93 | 97 | +4 |
| Speed | 82 | 74 | +8 |
| Control | 90 | 91 | +1 |
| Value | 78 | 71 | +7 |
| Index score | 88.5 | 88.6 | +0.1 |
Which to pick
Pick GPT-5.6 Sol unless Speed and Value is what decides it for you, which is exactly where Claude Opus 5 is the better answer.
Claude Opus 5
Opus 5 is the model that makes the rest of Anthropic's line-up hard to justify. It gives up a little at the very top of the reasoning range and takes half off the bill, while staying quick enough to sit inside an editor or an agent loop. If you are choosing one paid frontier model and do not want to think about it again this quarter, this is the honest answer.
Where it shines
- Frontier-class output without the flagship's price
- Fast enough for interactive use, unlike the tier above it
- Excellent at long-context reading of an existing codebase
GPT-5.6 Sol
Sol is the top of the GPT-5.6 line and the strongest model here on mathematics and formal reasoning, with a context window past a million tokens. It thinks for a long time before it answers, which is the point and also the bill. On everyday work it is comprehensively out-earned by the cheaper members of its own family, so treat it as a specialist rather than a default.
Where it shines
- Leads the field on mathematics and formal reasoning
- Context window past a million tokens, so whole corpora fit
- Thinking budget is exposed, so you can pay for depth only when you need it