GitHub Copilot

GitHub's incumbent AI assistant. VS Code, JetBrains, Neovim integrations. Lost some inline-completion mindshare to Cursor and agentic mindshare to Claude Code, but still the easiest enterprise rollout via GitHub.

Install via your IDE's extension/plugin marketplace. VS Code: Extensions (Ctrl+Shift+X), search "GitHub Copilot", install. JetBrains: Plugins marketplace, search "GitHub Copilot", install. Neovim: plugin + github/copilot.vim. After install, sign in with your GitHub account. A subscription is required: Copilot Individual ($10/month) or Copilot Business/Enterprise ($19–39/user/month). Once signed in, inline completions appear automatically as you type — grey ghost text suggesting the next code. Accept with Tab, reject with Esc. Copilot Chat: Ctrl+I (VS Code) or right-click → "Copilot → Start Code Chat" for a chat panel that can reference files, explain code, generate tests, or answer questions. Copilot's completions use context from open files, recent edits, and the cursor position — no prompt needed. For chat, describe what you want in natural language. Verify: open any file, type a function signature like function sortUsers(users: User[]): User[] { — Copilot should suggest the implementation body in grey text within 1–2 seconds. Time-to-first-completion: ~3 seconds after install and sign-in. No model selection or configuration needed — Microsoft manages the backend.

Best for: developers who want AI completions with the widest IDE support, lowest setup friction, and simplest pricing model, line-level and function-level code completion where the assistant fills in what you'd type anyway, team environments on GitHub Enterprise where Copilot integrates with org policies and audit, polyglot developers switching between IDEs (VS Code, JetBrains, Neovim) who want a consistent AI experience. Not suited for: autonomous multi-step coding tasks (use Claude Code or Cline), inline code editing beyond completions (use Cursor), developers who want model or provider flexibility (Copilot is Microsoft-managed), offline/air-gapped environments (requires GitHub auth and cloud connectivity), developers wanting to cap or audit per-user AI costs flexibly (Copilot is per-seat subscription, not usage-based).

Use GitHub Copilot for the lowest-friction AI completions across every major IDE — it's the default AI coding assistant with the widest IDE support and simplest signup (GitHub account). Switch to Cursor when you want an AI-native IDE with inline editing (Cmd+K) and agentic features beyond completions — Copilot is assistive, Cursor is transformative. Use Continue when you need provider flexibility or want to use local models — Copilot is Microsoft-managed. Use Cline or Claude Code for autonomous agentic coding — Copilot's agent mode (Copilot Edits) is newer and less mature than dedicated agent tools. Use Supermaven (now acquired by Cursor) for maximum completion speed at the cost of context depth. Use Aider for terminal git-native pair programming. Copilot's strength: it just works in every IDE with zero configuration. Its weakness: less context intelligence than Cursor's Tab model, slower to adopt cutting-edge AI features (agentic, inline editing), and provider lock-in to Microsoft/GitHub.

Problem: Completions are generic/low-quality or don't appear. Fix: Copilot's context window includes open tabs, the current file, and neighboring files. Keep related files open in tabs (even if hidden) to improve context. Copilot uses an implicit prompt from file extension and content — naming functions descriptively and including type annotations improves suggestion quality. If completions stop appearing, check the Copilot status bar icon (bottom-right in VS Code) — it shows availability. Problem: Error: Copilot could not connect to server. Fix: Copilot requires periodic token refresh via GitHub auth. Sign out and sign back in (VS Code: Accounts menu → Sign Out, then re-authenticate). Corporate proxies block Copilot's WebSocket connection — configure VS Code's proxy settings (http.proxy in settings). Firewall must allow outbound to *.githubcopilot.com. Problem: Copilot Chat can't see my project files. Fix: Copilot Chat in VS Code uses #file:path/to/file syntax in the chat prompt to reference files. The file must be in the workspace and opened at least once. For full workspace context, use Copilot's "Workspace" agent (Ctrl+I → select "Workspace" from the agent picker).