Claude Code Plan Mode: Think Before You Code

Plan mode is the feature that separates Claude Code from every other AI coding tool. Instead of jumping straight to code generation, Claude Code stops, thinks, and presents a plan for your approval before writing a single line.

This sounds simple. It's transformative.

Why Plan Mode Matters

The #1 cause of bad AI-generated code isn't the model's capabilities - it's starting implementation without understanding the problem. Without plan mode, AI tools generate code that works in isolation but conflicts with your architecture, duplicates existing functionality, or introduces patterns you don't want.

Plan mode fixes this by making Claude Code's reasoning visible and reviewable.

How It Works

When Claude enters plan mode, it:

1. Explores your codebase - Reads relevant files, understands existing patterns
2. Analyzes the request - Breaks your feature into implementation steps
3. Proposes an approach - Lists files to create/modify, architecture decisions, data flow
4. Waits for approval - You review, ask questions, or redirect

Only after you approve does it start writing code.

When to Use Plan Mode

Always use plan mode for:

• New features touching 3+ files
• Architectural decisions
• Database schema changes
• API design
• Any task where you'd want to review the approach first

Skip plan mode for:

• Single-file bug fixes
• Simple text changes
• Tasks where you've already specified exact implementation

Reviewing Plans Effectively

When Claude presents a plan, check:

• File list - Are these the right files? Missing anything? Touching files it shouldn't?
• Architecture - Does the approach align with your patterns?
• Data flow - How does data move between components?
• Edge cases - What happens on errors, empty states, race conditions?
• Dependencies - Does it introduce new dependencies? Are they necessary?

You don't need to validate every detail. Focus on structural decisions - those are expensive to change later.

Real Workflow Example

I needed to add Stripe payments to a SaaS application. Here's how plan mode played out:

My prompt: "Add Stripe subscription payments. Users should be able to subscribe to a Pro plan from the pricing page."

Claude's plan:

1. Install stripe package
2. Create /app/api/stripe/checkout/route.ts - Checkout session endpoint
3. Create /app/api/stripe/webhook/route.ts - Webhook handler
4. Update prisma/schema.prisma - Add subscription fields to User
5. Create /app/pricing/page.tsx - Pricing page with plan comparison
6. Add Stripe portal for subscription management
7. Create middleware to check subscription status

My review: I noticed it was going to add Stripe directly to the User model. I redirected: "Use a separate Subscription model linked to User." Claude adjusted the plan.

This 30-second review prevented a schema decision that would have been painful to refactor later.

Tips for Better Plans

Be specific about constraints: "Use existing Supabase auth, don't add a new auth system" prevents Claude from reinventing your auth.

Mention existing patterns: "Follow the same pattern as the /api/users endpoint" gives Claude a reference point.

Ask about trade-offs: "What are the trade-offs of this approach?" makes Claude surface considerations it might skip.

For more on configuring Claude Code for your workflow, see Claude Code Best Practices and System Prompt Configuration.

Frequently Asked Questions

How do I enter plan mode?

Can I modify a plan after Claude proposes it?

Does plan mode cost more?