OpenAI
gpt-5.5-pro-pre-release
Made by OpenAI. Released 2026-04-23. Accessibility not recorded. We hold no price for this model: no seller we can read lists it any more, so what follows is what was measured, not what it cost.
What it scores, by house
| Benchmark | House | Score | Evaluated | Scaffold |
|---|---|---|---|---|
| chess puzzles | Epoch AI | 0.6±0.05 | 2026-05-01 | xhigh |
| frontiermath | Epoch AI | 0.5±0.03 | 2026-04-23 | xhigh |
| frontiermath | Epoch AI | 0.5±0.03 | 2026-04-23 | high |
| frontiermath tier 4 | Epoch AI | 0.4±0.07 | 2026-04-23 | xhigh |
| frontiermath tier 4 | Epoch AI | 0.4±0.07 | 2026-04-23 | high |
| gpqa diamond | Epoch AI | 0.9±0.02 | 2026-04-24 | xhigh |
| otis mock aime 2024 2025near its ceiling | Epoch AI | 1.0±0.00 | 2026-04-24 | xhigh |
These scores are not comparable between houses and are not added up. A score is dated by when it was evaluated, not when the model was released, and a score without its scaffold is not a measurement — which is why both are printed.