Choose the tool.
Finish the task.
A practical decision guide for quick answers, finished deliverables and software work.
Chat, Work and Codex: Which One to Use
The video promises a full guide to Chat, Work and Codex. OpenAI describes Chat for quick conversation, Work for longer multistep deliverables, and Codex for software development. Availability depends on plan, workspace and device; this guide focuses on choosing well once the experience is available.
One useful step at a time.
- 01Name the output
- 02Choose a surface
- 03Give context
- 04Review the result
The three roles
| Experience | Use it when | Example output |
|---|---|---|
| Chat | You need an explanation, brainstorm or quick draft | A clear answer or first draft |
| Work | You need research, files, connected apps or a complete deliverable | A report, spreadsheet, deck or site |
| Codex | You need code changed, tested or reviewed | A working app, fix or review |
A task can move between experiences. For example, brainstorm in Chat, make a research brief in Work, and implement the website in Codex. Choose based on the next concrete output rather than the prestige of the tool.
Choose with a decision map
Ask four questions: What is the deliverable? What information is required? Does the task touch code? Where do the files live?
If the deliverable is a short answer and no files need editing, start in Chat. If it needs several steps, current sources or document creation, choose Work. If you need to inspect a repository, edit files, run tests or fix an app, choose Codex.
A connected app is available only when it is installed and authorized for that experience. A local file is available only when the task has access to it. Tell the assistant where to work and what success looks like.
Three starter prompts
Chat
Explain [topic] to a beginner in five bullets. Give one concrete example and two questions I should ask next.
Work
Research [topic] using current primary sources, then create a practical guide for [audience]. Include a source appendix, examples and a checklist. Verify facts that could have changed.
Codex
In this repository, fix [specific behavior]. First inspect the relevant files, then implement the smallest sound change. Run the applicable tests and show me what changed and what remains to verify.
Review the right evidence
For Chat, check the answer’s factual claims. For Work, inspect the finished artifact, citations and calculations. For Codex, review the diff, run the app and test the key path. The assistant can be wrong in any mode, so a review matched to the deliverable is the final step.
Sources & notes
Product details were checked on 5 October 2026. Menus, plans, and integrations can change. The video is the source of the lead-magnet promise; the links below support the practical instructions and corrections in this guide.
- ChatGPT Work and Codex: Current role of Chat, Work, and Codex.
- Plugins in ChatGPT: Plugin setup and availability.
- Projects in ChatGPT: Project files and instructions.
The guide reflects OpenAI’s current product descriptions, not an assumption that every plan has identical access.