What is Claude Code plan mode?
A mode where Claude Code can read your code and propose a plan but does not edit files or run commands until you approve. It lets you check the approach before anything changes.
Claude Code
Claude Code plan mode: plan before you build
Plan mode makes Claude Code read your code and write a plan without editing files or running commands, so you approve the approach before anything changes. Start a session in plan mode, or press Shift+Tab to cycle to it, review the plan, then let Claude build.
Updated September 30, 2026 · By Dr. Sam Sammane
From the TheoSym channel
Claude Code: plan before you build
Published September 21, 2026
A 54-second TheoSym short on why to have Claude Code plan the change before it builds anything.
Watch on YouTubeWhat plan mode does
In plan mode, Claude Code can explore your project, read files and ask questions, but it does not make changes. It comes back with a step-by-step plan for you to approve, adjust or reject.
That gives you a checkpoint at the cheapest possible moment. Fixing a wrong plan costs a sentence. Fixing a wrong implementation costs a diff, a review and a revert.
When to use plan mode
For a one-line fix, plan mode is more ceremony than it is worth. Use it when the cost of a wrong start is high.
- Changes that touch several files or layers
- Code you did not write or do not yet understand
- Refactors, migrations and dependency upgrades
- Anything you would want a teammate to describe before they start
How to start plan mode
- Open Claude Code in your project.
- Switch to plan mode with Shift+Tab, which cycles through the permission modes, or start the session in plan mode from the command line.
- Describe the change and the outcome you want.
- Read the plan. Ask for changes until it matches what you would have done yourself.
- Approve the plan and let Claude implement it.
Keys and flags change between releases. Check the Claude Code documentation for the current syntax.
What a good plan contains
If the plan does not say how it will verify the result, ask it to add that. A plan without a check is a wish.
- The files it will change and why
- The order of the steps
- The tests it will add or run to prove the change works
- The risks and what it is not going to touch
Plan first, then enforce the rules
A plan is a request that Claude can misread. Pair plan mode with rules that always apply: write your limits down in the project instructions, and enforce the non-negotiable ones with Claude Code hooks. Our Claude Code best practices page puts the whole workflow together.
Claude Code plan mode: common questions
How do I turn on plan mode in Claude Code?
Press Shift+Tab to cycle through the permission modes until plan mode is active, or start the session in plan mode from the command line. Check the Claude Code docs for the current flag.
When should I use plan mode?
Use it for multi-file changes, unfamiliar code, refactors and migrations, where a wrong start is expensive. Skip it for small, obvious edits.
Does plan mode change any files?
No. In plan mode Claude explores and proposes. Changes begin only after you approve the plan.
What should I do if the plan is wrong?
Tell Claude what is wrong and ask it to revise. Correcting a plan takes a sentence, which is why planning first is cheaper than fixing the code afterwards.
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