OpenAI Codex

OpenAI's coding agent that writes, reviews and fixes code in the cloud or terminal.

What is OpenAI Codex?

Codex is OpenAI's software engineering agent. It can work on tasks in a cloud sandbox, in your terminal through the Codex CLI or inside your editor, and it can propose pull requests and review code. It comes with paid ChatGPT plans.

Best for: Developers who want to hand off whole coding tasks.

What you can do with OpenAI Codex

Ask the agent to fix a bug and open a pull request
Generate tests for a module
Review a teammate's changes

Key features

Cloud tasks that run in parallel
Open-source Codex CLI
IDE extension
Code review on pull requests

OpenAI Codex pros and cons

Pros

Works across cloud, terminal and editor
Strong at multi-step tasks

Cons

Needs a paid ChatGPT plan

OpenAI Codex pricing

PaidIncluded with paid ChatGPT plans

OpenAI Codex is a paid tool; there is no ongoing free plan. Plans change often, so check the official site for current prices.

How to get started

Open openai.com and create a free account or start the trial.
Try one real task first: ask the agent to fix a bug and open a pull request.
Compare the result with GitHub Copilot or Cursor, then keep the one that fits how you work.

Compare OpenAI Codex

Side-by-side comparisons of features, pricing, pros and cons.

OpenAI Codex alternatives

Other tools that do a similar job, ranked by our editors.

All OpenAI Codex alternatives

GitHub Copilot
Free + PaidEditor's pick
AI pair programmer inside VS Code, JetBrains and GitHub.
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Cursor
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An AI-first code editor that understands your whole project.
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Claude Code
Paid
Anthropic's agentic coding tool for the terminal, IDE and web.
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Lovable
Free + Paid
Build a working web app by describing it in chat.
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Replit
Free + Paid
Code, build and deploy apps in the browser with an AI agent.
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Bolt.new
Free + Paid
Prompt, run and deploy full-stack apps in the browser.
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Top AI coding tools

How OpenAI Codex compares with the best in AI Coding.

1. GitHub Copilot
Free + Paid
AI pair programmer inside VS Code, JetBrains and GitHub.
2. Cursor
Free + Paid
An AI-first code editor that understands your whole project.
3. Claude Code
Paid
Anthropic's agentic coding tool for the terminal, IDE and web.
4. OpenAI API Platform
Paid
OpenAI's developer platform for building apps with GPT, image, audio and embedding models.
5. Claude Developer Platform
Paid
Anthropic's console and API for building with the Claude family of models.

See all 26 AI coding tools

OpenAI Codex FAQ

What is OpenAI Codex?

Is OpenAI Codex free?

OpenAI Codex is a paid tool; there is no ongoing free plan. Included with paid ChatGPT plans. Check the official site for current limits and prices.

What can you do with OpenAI Codex?

With OpenAI Codex you can ask the agent to fix a bug and open a pull request; generate tests for a module; review a teammate's changes.

Who is OpenAI Codex best for?

Developers who want to hand off whole coding tasks.

Does OpenAI Codex have an app?

Yes. Besides the web version, OpenAI Codex has apps for Mac, Linux and Windows.

Who makes OpenAI Codex?

OpenAI Codex is made by OpenAI.

What are the best alternatives to OpenAI Codex?

Popular alternatives include GitHub Copilot, Cursor, Claude Code and Lovable. See the full ranking on our AI Coding page.

AltFTool is not affiliated with OpenAI Codex. This summary was written by our editors from the tool's public information. Browse all 451 AI tools