Cursor is a fork of VS Code customized for AI. It pioneered Tab-to-Complete (Copilot++) and Composer (Multi-file edits). In 2025, it is the leading "AI Native" editor.
When to Use
Heavy AI Usage: If you copy-paste to ChatGPT 50 times a day, use Cursor.
Legacy Refactoring: "Rewrite this entire legacy class to use React Hooks" works across multiple files.
Speed: The "Shadow Workspace" indexing makes AI answers aware of full context instantly.
Core Concepts
Composer (Cmd+I)
A floating window that can edit multiple files simultaneously. "Add a
verified
field to the User model and update all call sites."
Tab (Copilot++)
Predicts your next cursor movement, not just text. It feels like mind-reading.
Indexing
Cursor locally indexes your code (embeddings) so the LLM knows about function definitions in other files without you opening them.
Best Practices (2025)
Do:
Use Rules: Add a
.cursorrules
file to repo root to instruct the AI (e.g., "Always use Tailwind", "No try/catch blocks").
Import VS Code Extensions: It takes 1 click to migrate everything from VS Code.