GPT-5.3-Codex
OpenAI🇺🇸
openai/gpt-5.3-codexGPT-5.3-Codex is OpenAI's February 2026 Codex-native coding agent, pairing frontier coding performance with general reasoning for long-horizon, real-world engineering work. It supports steering the agent mid-task and is notable as a model OpenAI used to help build itself.
Cost rate
2.5x
Context
400K
Released
Feb 24, 2026
Input
TextImageFile
Output
Text
Support
ReasoningTool callingStructured outputs
Best at
The categories where this model ranks highest.
No top-ranked categories found.
Performance
Median latency and throughput measured across recent requests.
Throughput126 tok/s
Latency