The /plan mode and the Think keyword are two different, yet complementary, features in Claude Code that improve how Claude handles complex tasks.
🤔 Plan Mode vs. Extended Thinking: The Key Difference
| Plan Mode (/plan) | Extended Thinking (e.g., Think) |
|---|---|
| Creates a read-only phase for analysis and creating an execution plan before any changes are made. | Gives Claude additional computation time to reason "deeply" on a specific problem before acting. |
| Breadth-first research. It's designed to explore codebases, understand structures, and draft comprehensive plans by reading many files without risk of edits. | Depth-first analysis. It focuses on intensively reasoning through a single task or a set of gathered information to reach a precise, high-quality solution. |
| Use the /plan command or press Shift+Tab twice in the terminal. | Include keywords like Think, Think more, or ULTRATHINK directly in your prompt to Claude. |
| Puts Claude into a different operational mode where file editing and command execution tools are restricted. | Is a prompting technique that requests more internal reasoning steps within the current mode. |
🔄 How They Work Together
These features are designed to be used together in an "Explore, Plan, Code, Commit" workflow. You typically start in Plan Mode for safe exploration, then use extended thinking to refine the solution before execution.
💡 When to Use Which Feature
Use Plan Mode (/plan) when starting a new, complex feature that touches many files, or when you need to safely explore an unfamiliar codebase without the risk of accidental edits.
Use Extended Thinking keywords when Claude is working on a difficult, focused problem (like a tricky bug or algorithm) and you want to ensure it dedicates sufficient reasoning effort before giving you an answer.
In short, Plan Mode creates a safe, structured environment for broad planning, while the Think keyword encourages deep, focused reasoning on a problem. They are most powerful when used together in sequence.
/plan
Enabled plan mode
PROMPT
1can you create 10 similar scripts that provide unique greetings
can you create 10 similar scripts...
1. Use these greetings
1. Yes, clear context and auto-accept edits (shift+tab)
1. Yes, clear context and auto-accept edits (shift+tab)
Done
PROMPT
1update the CLAUDE.md in line with last update
Updated CLAUDE.md
PROMPT
1Refactor the script files separating out the greeting string creation from the text output. Think hard about this update
Refactor the script files...
Thinking...
Approach 4
3. Shared Module
1. Yes, clear context and auto-accept edits (shift+tab)
Refactoring all scripts...
All 11 scripts run successfully...
./Aloha.ps1