o3-pro review, price and benchmarks (2026)

legacy paid api reasoning

Provider

Statuslegacy

AA Intelligence Index32.5 (September 8, 2026 snapshot)

Releasedn/a

Context windown/a

Modalitiesn/a

API price $/1M (in / out)n/a

Speedn/a

AccessAPI (legacy reasoning line)

In one line

The 2025 deep-reasoning specialist - slow and dated now, but a milestone in chain-of-thought models.

Coding58

Reasoning66

Writing45

Agents & tools50

Category scores (0-100) are WhichAI blended ratings: public category leaderboards plus editorial judgment. Guidance, not official measurements.

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Artificial Analysis Intelligence Index, 2026 rebased scale (top models ~ 55-66). Snapshot: September 4, 2026 (BenchLM mirror), retrieved September 8, 2026. Specs and prices come from the OpenRouter public model list on the same date. Models nobody has measured carry no index score at all and never enter a ranking: where an estimate exists it is shown separately and labelled unmeasured. Context, price, modality and release dates come from the public OpenRouter model list (retrieved September 8, 2026) and vendor pages. Missing values are not published or not yet verified - shown as -. Sources are linked inside the app (Model guide and About > Methodology).