GPT-5.3-Codex
OpenAI🇺🇸 United States
First model combining the Codex and GPT-5 training stacks — best-in-class code generation plus general-purpose reasoning in one model, ~25% faster than its predecessor.
Context window400K tokens
Input / 1M tokens$1.75
Output / 1M tokens$14
Version History
gpt-5-3-codex-launchmajor
GPT-5.3-Codex launches. First model combining the Codex and GPT-5 training stacks — best-in-class code generation plus general-purpose reasoning in one model, ~25% faster than its predecessor.
Benchmark Scores
Full leaderboard →91.5%
GPQA
131.0 tokens_per_sec
Speed (tok/s)