OpenAI Codex
OpenAI's coding agent across CLI, IDE, desktop and cloud.
OpenAI · open source · checked Oct 22, 2026
What it is
Codex runs on GPT-6-family models in the CLI, IDE extension, desktop app, web and iOS, with cloud tasks, code review and Slack integration. Included in ChatGPT plans.
Use cases
- →ChatGPT subscribers who want an agent
- →Parallel cloud tasks
- →Automatic code review
Pros
- +Comes with ChatGPT you may already pay for
- +Strong GPT-6.1 Sol models
- +CLI is open source
Cons
- −Usage shared with ChatGPT Work
- −Best features on higher tiers
Where it ranks
- #2 Best Coding Agents & CLI Agents
Comes with ChatGPT plans from $8/mo, strong GPT-6.1 Sol models, CLI + IDE + cloud.
Compare OpenAI Codex
FAQ
How much does OpenAI Codex cost?
Included in ChatGPT: Free $0, Go $8/mo, Plus $20/mo, Pro from $100/mo ($100/$200/$500 tiers), Business $20/user/mo annual ($25 monthly). (As checked on 2026-10-22; confirm on https://developers.openai.com/codex/pricing.)
What is OpenAI Codex best for?
#2 in Best Coding Agents & CLI Agents: ChatGPT subscribers.
What are the best alternatives to OpenAI Codex?
Claude Code (Anthropic's agentic coding tool for terminal, IDE and cloud); Amp (Frontier coding agent with cloud 'orbs' and BYO subscriptions); GitHub Copilot (VS Code, CLI, cloud agent) (Copilot in your editor, terminal and GitHub).
Is OpenAI Codex open source?
Yes, OpenAI Codex is open source (or has an open-source core).