Claude Code Plan Mode

Plan mode lets Claude Code study your project and propose a strategy before it touches a single file. Large changes go smoother when you review the plan first. Mistakes shrink because you catch a wrong direction while it still costs nothing.

What Plan Mode Does

An architect draws blueprints before the builders arrive. Plan mode works the same way. Claude Code reads files, searches the code, and writes a step-by-step plan. Your source files stay untouched until you approve.

NORMAL MODE                    PLAN MODE
-----------                    ---------
Prompt                         Prompt
  ↓                              ↓
Edits files right away         Reads and explores only
                                 ↓
                               Shows a written plan
                                 ↓
                               You approve or revise
                                 ↓
                               Editing begins

How to Start Plan Mode

• Press Shift+Tab until the mode indicator shows plan mode.
• Type /plan before a prompt to plan a single request.
• Launch with claude --permission-mode plan to start the whole session in plan mode.

A Worked Example

Suppose a shop website needs a discount-code feature. Open plan mode and send this prompt:

Add discount codes to the checkout page.
Customers enter a code and see the new total.
Explain which files you would change.

Claude Code studies the checkout files and replies with a plan similar to this:

PLAN
1. Add a discount field to checkout.html
2. Create discounts.js with the code list
3. Update cart.js to subtract the discount
4. Add tests for valid and expired codes

Read the plan like a checklist. Ask questions about any step that looks unclear. Request a change in plain language, such as "Skip step 4 for now and keep codes in a separate file."

Approving the Plan

Claude Code offers approval choices once the plan looks right. Approving exits plan mode and starts the editing. Some choices keep the permission prompts, and others let edits flow without asking. Pick the one that matches your comfort level.

When Plan Mode Pays Off

Situation	Why Planning Helps
Changes touching many files	You see the full scope before work starts
Unfamiliar codebase	Claude Code explains the structure while you watch
Risky refactoring	You spot dangerous steps early
Vague requirements	Questions surface missing details

When to Skip Plan Mode

Small tasks do not need a blueprint. Fixing a typo, renaming one variable, or adding a single comment takes seconds in normal mode. A rule of thumb helps: if you could describe the full change in one sentence, skip planning.

A Strong Planning Habit

Explore

Ask Claude Code to read the relevant files and summarize how they work.

Plan

Request a written plan with the files and the order of changes.

Build

Approve the plan and let the editing begin.

Verify

Run the tests and review the changes before you commit.

EXPLORE → PLAN → BUILD → VERIFY

Plan Mode Prompt Ideas

Strong planning prompts name the goal, the limits, and the format of the answer. Try "Plan a way to move user settings into a separate file. List every file you would touch and flag risks." Another useful request asks for options: "Give two approaches and explain the trade-offs." Comparing options helps beginners learn why developers choose one design over another. Save a good plan in a text file when the work will span several days.

Reviewing a Plan Like a Pro

A good plan names specific files, lists changes in order, and mentions tests. Vague plans such as "update the code" deserve a follow-up question. Ask Claude Code which step carries the most risk. Ask what would break if a step failed. These questions turn a plan into a shared understanding between you and the assistant, and they build your own skills with every project.

Key Points

• Plan mode reads and proposes without changing files.
• Shift+Tab, /plan, and a launch option all start it.
• You review and revise the plan before approving.
• Plan mode suits large, risky, or unclear tasks.
• Small one-sentence changes run fine in normal mode.