Plan Mode

Plan Mode is a mode that makes an AI coding tool figure out what to do and in what order before it actually starts writing code.

Think of building a house. If a bricklayer starts stacking bricks the moment they arrive, the room layout can end up wrong or the plumbing can end up tangled. So instead, you draw up a blueprint first, decide where the doors and pipes will go, and only then start construction. Plan Mode is having the AI go through that blueprint stage first.

It's especially useful for tasks that touch many parts of a codebase, like adding a new feature, refactoring old code, or tracking down the cause of a bug. Jumping straight into edits without a plan makes it easy to fix one thing and break another; sketching out the whole picture first cuts down on these mistakes.

Covering a slash-command guide for the GitHub Copilot app, an article explains that "the /plan command helps break a task down before any code is written." Running it switches the session into Plan mode.

A common misconception is that Plan Mode means no code gets written at all. That's not the case. The planning stage simply steps in once before code is written, and once the plan is settled, the work moves on to actually writing the code.

Type /plan into an AI coding tool's chat window, followed by a description of what you want to do.

Example: /plan I want to add a password reset feature to the login page

See whether the AI, instead of writing code right away, first lays out a step-by-step plan for which files it will touch and in what order it will work.