GitHub Copilot, powered by OpenAI Codex and now GPT-4, was the tool that brought AI-assisted coding into mainstream development. Two years after launch, it remains the market leader.
**Code Completion**
Copilot's inline suggestions are fast and contextually aware. It reads surrounding code, comments, and file structure to suggest relevant completions ranging from single lines to entire functions.
**Multi-file Context**
The newer Copilot Enterprise tier understands your entire repository, allowing it to suggest code that follows your project's conventions and references existing utilities.
**IDE Support**
Copilot works in VS Code, Visual Studio, JetBrains IDEs, Neovim, and more. The VS Code integration is the most polished.
**Copilot Chat**
The chat interface allows you to ask questions about your codebase, request refactors, generate tests, and explain unfamiliar code — all within the IDE.
**Accuracy**
Copilot accepts rate (how often developers keep suggestions) averages around 30-35% in studies, which is high for the category. It performs best with Python, JavaScript, and TypeScript.
**Pricing**
$10/month for individuals, $19/month per user for business. Free for verified students and open-source maintainers.
**Verdict**
GitHub Copilot is the most mature and widely supported AI coding assistant. Worth every penny for professional developers.