OpenAI Codex
OpenAI Codex is best for handing off parallel coding tasks in the background. It ranks #2 in AI coding agents with 4.3/5.
OpenAI's coding agent, in the terminal, the IDE and the cloud.
Included with ChatGPT plans Official site
Score breakdown
Draft scores, checked 2026-10-27. Output quality counts double in the overall score. How we rank.