Why plan mode matters more than you think

November 9, 2025

Part of the Claude Code in Practice series

Series outline: 1. Why Claude Code is different • 2. How Claude reads your codebase • 3. Writing tasks Claude can complete • 4. Plan mode workflow • 5. Real-world scenarios • 6. MCP and skills • 7. Optimizing for speed • 8. Building your workflow

In every successful AI adoption I’ve observed, this is where teams start. Plan mode is what separates tools you can trust from tools that make you nervous. It is the difference between crossing your fingers and hoping the AI does the right thing, versus having a reviewable process where teams stay in control. Once engineers understand this workflow, adoption accelerates.

What is plan mode

Plan mode is a workflow where Claude explores your codebase, creates a detailed implementation plan, and waits for your approval before making any changes. You get to review what Claude intends to do, ask questions, request modifications, and only proceed when you are confident in the approach.

Plan mode workflow demonstration

This might sound like extra overhead. Why not just let Claude start coding immediately? Because AI is not perfect. It makes assumptions, misunderstands requirements, and sometimes chooses suboptimal approaches. Plan mode catches these issues before they become bad code in your repository.

The planning phase

When you give Claude a task in plan mode, it starts by exploring. It searches for relevant files, reads existing code, understands patterns, and figures out what needs to change. This exploration is methodical. Claude uses the same tools you would use: searching for patterns, reading definitions, tracing dependencies.

Once Claude understands the codebase, it creates a plan. This plan includes what files need to change, what the changes will accomplish, and what approach it will take. The plan is written in plain language, not code. You can read it quickly and spot problems before any code is written.

Reviewing and approving plans

The review step is where you add judgment. You know things Claude does not: your team’s conventions, upcoming changes that might conflict, business constraints that are not in the code. Reading the plan takes seconds, but it can save you from costly mistakes.

When reviewing a plan, ask yourself:

If something looks wrong, you can ask Claude to revise the plan. If it looks good, you approve and Claude executes. You stay in control of what happens in your codebase.

Slicing plans into manageable chunks

Large tasks produce large plans. When a plan feels overwhelming, slice it. Break the work into smaller pieces that you can verify independently.

For example, if Claude plans to refactor an authentication system across 15 files, you might slice it into:

  1. Update the core auth module
  2. Migrate login and signup flows
  3. Update session management
  4. Migrate protected route components

Each slice is a complete, testable unit of work. You can verify each piece before moving to the next. If something breaks, you know exactly which slice caused it. This makes debugging trivial compared to reviewing one giant change.

The iterative workflow

Plan mode is not a one-shot process. It is iterative. The cycle looks like this:

  1. Describe the task to Claude
  2. Review the plan Claude creates
  3. Slice or modify if needed
  4. Approve and execute one slice
  5. Verify the results (run tests, check behavior)
  6. Repeat for the next slice

This cycle keeps you in control while letting Claude do the heavy lifting. You make decisions, Claude implements them. You verify results, Claude fixes issues. The partnership is clear: Claude handles tedious implementation details, you handle judgment and verification.

When to interrupt and redirect

Sometimes Claude gets stuck or heads in the wrong direction. Plan mode makes this obvious because you see the plan before execution. If the plan looks wrong, stop and redirect.

You can interrupt at any point to:

This is much better than letting Claude finish a wrong implementation and having to undo everything.

Course-correction without starting over

One of the best parts of iterative work is that mistakes are cheap. If a slice does not work as expected, you only need to fix that slice. The previous slices are already done and verified. You do not start over from scratch.

This is why slicing matters. Small units of work mean small units of correction. You maintain forward progress even when things do not go perfectly.

Why this beats “just let Claude do everything”

You might think giving Claude full autonomy would be faster. Just describe what you want and come back when it is done. In practice, this leads to:

Plan mode trades a few seconds of review time for confidence in the results. You catch issues early when they are easy to fix. You guide Claude toward good solutions instead of hoping it guesses right.

The workflow feels slower at first, but it is actually faster because you avoid the costly mistakes that come from blind automation.

The key insight

Plan mode transforms AI coding from a gamble into a process. You stop hoping the AI does the right thing and start verifying it will. The plan → review → slice → iterate cycle becomes second nature. You work faster because you trust the process, not because you trust the AI to be perfect.

This workflow is how experienced Claude Code users work. It is the foundation for everything else. Master this, and the rest of Claude Code becomes easy.

Now that you understand the workflow, let’s look at real scenarios where plan mode shines.

Previous: ← Writing tasks Claude can complete | Next: Real-world scenarios →