Copilot, Cursor, Claude Code, Codex: Which AI Tool for What

The AI coding tool landscape is confusing. Four major tools, different interfaces, different strengths, and no clear guidance on when to use which. Here is my practical breakdown after using all four on real projects.

The Four Tools at a Glance

| Tool | Interface | Best For | |------|-----------|----------| | GitHub Copilot | IDE inline suggestions | Line-by-line completions | | Cursor | IDE with AI chat | Single-file editing and refactoring | | Claude Code | Terminal agent | Multi-file projects, scaffolding | | Codex | Cloud agent | Background tasks, CI integration |

GitHub Copilot: The Autocomplete

Copilot lives in your IDE and suggests the next line of code as you type. It is the simplest tool to adopt because it requires zero workflow change. You type, it suggests, you press Tab.

Best for: repetitive code patterns, boilerplate, writing code you already know how to write but do not want to type. Worst for: complex logic, multi-file changes, understanding existing code.

Cursor: The Smart Editor

Cursor wraps VS Code with deeper AI integration. You can highlight code and ask questions, request refactors, or generate new code based on context from open files. The inline diff preview before accepting changes is excellent for precision work.

Best for: editing existing code, refactoring single files, understanding unfamiliar code. Worst for: creating new projects from scratch, multi-file orchestration.

Claude Code: The Project Agent

Claude Code is a terminal-based agent that operates at the project level. It reads your entire codebase, creates files, runs commands, and iterates on feedback. It thinks in terms of features and modules, not individual lines.

Best for: scaffolding new features, multi-file refactoring, git operations, project-level understanding. Worst for: quick inline edits (Cursor is faster for that).

Codex: The Cloud Builder

Codex runs in the cloud asynchronously. You give it a task and come back later for the result. It can run tests, install dependencies, and create pull requests without occupying your local terminal.

Best for: background tasks, CI integration, tasks you want to run while doing other work. Worst for: interactive development where you need immediate feedback.

My Daily Workflow

I use three of these four tools daily:

Morning: Claude Code to scaffold new features and run project-level tasks
Midday: Cursor to fine-tune implementations and edit specific files
Background: Codex for tasks I can fire-and-forget while working on other things
Always on: Copilot for basic autocomplete in Cursor (they stack)

How to Choose

Ask yourself one question: 'What scope am I working at?'

Line scope: Copilot
File scope: Cursor
Project scope: Claude Code
Background scope: Codex

The best setup is all four, layered. They do not compete. They complement.

See the Claude Code docs and Cursor docs for getting started.