GPT-5.3-Codex System Card

📰 OpenAI News

GPT-5.3-Codex combines coding performance with reasoning and professional knowledge capabilities

advanced Published 5 Feb 2026

Action Steps

Explore GPT-5.3-Codex's coding capabilities
Evaluate its reasoning and professional knowledge features
Integrate GPT-5.3-Codex into development workflows to improve efficiency and accuracy

Who Needs to Know This

Software engineers and AI researchers on a team can benefit from GPT-5.3-Codex's capabilities to improve coding efficiency and accuracy, while product managers can leverage its professional knowledge to inform product development decisions

Key Insight

💡 GPT-5.3-Codex combines state-of-the-art coding performance with advanced reasoning and professional knowledge capabilities