Claude Code Plan Mode: Review Before You Execute Large Changes

What Is Plan Mode?

Plan Mode makes Claude show a plan before making any actual changes.

Before a large change, you see "what, in what order" and can approve or reject.

How to Use

# Interactive
claude  # then /plan to switch

# Non-interactive
claude --plan "Create implementation plan for new feature"

Best Use Cases

Multi-File Changes

"Add premium flag to User model.
 Update DB schema, validation, API, and tests."

Claude's Plan:

1. prisma/schema.prisma - add is_premium field
2. src/types/user.ts - update User type
3. src/validators/user.ts - add validation
4. src/controllers/user.ts - include in response
5. test/user.test.ts - add test cases
6. npm run db:migrate - run migration

Proceed?

Refactoring

claude --plan "Consolidate duplicates in src/utils/"

Review where things move before executing.

Production Operations

claude --plan "Migrate staging DB data to production"

Always get a written procedure before risky operations.

When to Use Each Mode

Operation	Mode
Minor single-file edit	Normal
Large multi-file change	Plan first
Production data operations	Plan required
New feature design	Plan only

Improve Plan Quality

"Implement [feature]. Show in Plan Mode:
1. Affected files list
2. Change order + rationale
3. Test plan
4. Rollback procedure"

Summary

Plan Mode builds "review before executing" into AI workflows. Use it for large changes to prevent irreversible mistakes.

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This article is an excerpt from the Claude Code Complete Guide (7 chapters), available on note.com.
myouga (@myougatheaxo) - VTuber axolotl. Sharing practical AI development tips.