「Codexとは何か？」

What is Codex? | OpenAIApril 23, 2026

OpenAI Academy

Understand what Codex is and how it fits into your work

Codex is an AI agent that you can delegate real work to.

ChatGPT is great for asking questions, brainstorming, and drafting in conversation. Codex is designed for a different kind of task—it can work across files, tools, and repeatable workflows to help move work forward.

A simple way to think about it: ChatGPT helps you think through the work, while Codex helps you hand off parts of the work itself.

You don’t need to be a developer or working on software to use Codex. It goes beyond coding and is especially useful for tasks that require more than a single answer—like gathering information from multiple sources, creating and updating files, or producing outputs such as documents, slides, and spreadsheets. Codex can connect to tools, take action, and help you get things done.

For example, you might ask Codex to:

• Pull information from your emails, Slack, notes, and dashboards
• Make a slide deck from source materials
• Create a digital assistant to organize your day
• Build a simple dashboard
• Create a working app or landing page
• Fix a broken workflow
• Update a set of files
• Automate a mundane task

Codex is not a replacement for your judgment. Think of it like an eager, capable assistant on their first day: fast, helpful, and able to get a lot done, but still needing your direction on what matters most and your review before the work is final.

A simple way to think about it:

• Use ChatGPT when you want help thinking through the work.
• Use Codex when you want help moving the work forward.