GPT 5.3 Codex
Overview
GPT-5.3-Codex is OpenAI’s most capable agentic coding model, combining GPT-5.2-Codex’s frontier coding with GPT-5.2’s reasoning in one model that is ~25% faster, tops SWE-Bench Pro and Terminal-Bench, and runs long, tool-using workflows on a computer.
About OpenAI
OpenAI is a technology company that specializes in artificial intelligence research and innovation.
