Model
OpenAI o3
by OpenAI
Family
o-series (reasoning)
Context window
200,000 tokens
Open weights
No
Release date
2025-04-16
Benchmark notes
Third-generation reasoning model; makes 20% fewer major errors than o1 on difficult real-world tasks per external expert evaluations, particularly excelling in programming, business consulting, and scientific hypothesis generation. o3-pro variant (released June 2025) uses extended compute for highest reliability. o3 snapshots scheduled for deprecation December 11, 2026.