Epoch
gpt-5.5-pro
Made by OpenAI. Released 2026-04-23. Accessibility not recorded. Cheapest standard rate we hold: $180 per million output tokens, at short context.
What it costs
| Tier | Kind | In | Out | Cached in | From |
|---|---|---|---|---|---|
| batch | text · long | $15 | $90 | — | seller |
| batch | text · short | $15 | $90 | — | seller |
| flex | text · long | $15 | $90 | — | seller |
| flex | text · short | $15 | $90 | — | seller |
| standard | text · long | $60 | $270 | — | seller |
| standard | text · short | $30 | $180 | — | seller |
per million tokens, US dollars. * marks a rate from a single registry or two that disagree — the best available number rather than a confirmed one. Every other row is confirmed against a seller or a licensed index.
What it scores, by house
| Benchmark | House | Score | Evaluated | Scaffold |
|---|---|---|---|---|
| frontiermath tier 4 v2 | Epoch AI | 0.8±0.07 | 2026-06-12 | xhigh |
| frontiermath tiers 1 3 v2 | Epoch AI | 0.9±0.02 | 2026-06-12 | xhigh |
| arc aginear its ceiling | collected by Epoch AI | 0.9 | — | xhigh |
| arc aginear its ceiling | collected by Epoch AI | 1.0 | — | high |
| arc agi 2 | collected by Epoch AI | 0.8 | — | xhigh |
| arc agi 2 | collected by Epoch AI | 0.8 | — | high |
| critpt | collected by Epoch AI | 0.3 | — | xhigh |
| dtbenchnear its ceiling | collected by Epoch AI | 1.0 | — | xhigh |
| lmca | collected by Epoch AI | 53.9 | — | xhigh |
| simplebench | collected by Epoch AI | 0.8 | — | high |
| simplebench | collected by Epoch AI | 0.8 | — | unknown |
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.
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