OpenAI Codex
OpenAI's coding agent for the terminal, IDEs, desktop app and cloud
What is OpenAI Codex?
OpenAI Codex is OpenAI's coding agent. It helps explore and understand code, build features, review code and fix failures. It runs as an open-source command-line tool, an IDE extension for VS Code, Cursor and Windsurf, a desktop app and a cloud agent, and every ChatGPT plan includes some Codex use.
Good for
- Building a small feature from a plain-language description
- Reviewing code changes before merging
- Investigating and fixing failing builds
Key features
- Open-source Codex CLI (Apache-2.0) for macOS, Linux and Windows
- IDE extension for VS Code, Cursor and Windsurf
- Codex desktop app
- Cloud agent (Codex Web) at chatgpt.com/codex
- Code review and fixing of issues and failures
- Sign in with a ChatGPT plan or use an API key
Limitations to know about
- Usage limits depend on the ChatGPT plan, the model and task size, measured per five-hour window
- Free and Go include only limited Codex access
- API-key use is billed separately at API rates
OpenAI Codex pricing
| Plan | Price | What you get |
|---|---|---|
| ChatGPT Free | $0 | Explore Codex on quick coding tasks |
| ChatGPT Go | $8/month | Limited Codex access |
| ChatGPT Plus | $20/month | Expanded Codex usage |
| ChatGPT Pro | From $100/month | 5x or 20x more Codex usage than Plus |
| Business, Enterprise and API key | Business $20/user/month billed annually ($25 monthly); Enterprise and Edu via sales; API key at standard API rates | Codex for teams, or pay per token with an API key |
Free plan limits: ChatGPT Free includes limited Codex use for quick coding tasks; Free and Go use GPT-6 Luna at standard speed in the desktop app, subject to rollout
OpenAI Codex alternatives
Claude Code
Anthropic's agentic coding tool for the terminal, IDEs, desktop and web
GitHub Copilot
GitHub's AI coding assistant for code completion, chat, agents and review
Cursor
AI code editor with agents that write and change code
Devin Desktop
AI code editor from Cognition, renamed Devin Desktop in June 2026
Mistral Vibe
Mistral AI's assistant for chat, work tasks and coding, now called Vibe
Lovable
AI app and website builder that creates apps from chat prompts
Head to head: OpenAI Codex vs Claude Code
Frequently asked questions
Is OpenAI Codex free?
OpenAI Codex has a free plan. ChatGPT Free includes limited Codex use for quick coding tasks; Free and Go use GPT-6 Luna at standard speed in the desktop app, subject to rollout. Paid plans start at $8/mo.
How much does OpenAI Codex cost?
OpenAI Codex's cheapest paid plan, ChatGPT Go, costs $8 a month billed monthly. Codex comes with ChatGPT plans; Plus ($20/month) expands Codex usage. Codex can also be used with an API key at standard API rates. There is also an enterprise plan priced on request. Prices as published on OpenAI Codex's pricing page on 23 September 2026.
What is OpenAI Codex used for?
OpenAI Codex is OpenAI's coding agent. People use it for building a small feature from a plain-language description, reviewing code changes before merging and investigating and fixing failing builds.
What are the alternatives to OpenAI Codex?
Tools that do a similar job include Claude Code, GitHub Copilot, Cursor, Devin Desktop and Mistral Vibe. Each has its own page here with its plans, limits and prices.
Who makes OpenAI Codex?
OpenAI Codex is made by OpenAI, based in San Francisco, California, US. The company was founded in 2015.
Sources
Every fact on this page comes from OpenAI's own pages, read on the dates shown.
- learn.chatgpt.com/docs/pricing (plans that include Codex, prices, usage limits, API-key billing) read 23 September 2026
- learn.chatgpt.com/docs (what Codex does and where it runs) read 23 September 2026
- github.com/openai/codex (CLI licence, OS support, sign-in options, IDE extension, app, Codex Web) read 23 September 2026
- en.wikipedia.org/wiki/OpenAI (company founded and HQ) read 23 September 2026