Cursor vs Copilot vs Codeium: The Definitive 2026 Comparison

Three AI coding tools dominate developer discussions in 2026: Cursor, GitHub Copilot, and Codeium (now Windsurf). Each takes a fundamentally different approach to AI-assisted development. We ran all three through identical coding tasks — 50 code completion challenges, 20 multi-file editing tasks, and 10 complex refactoring scenarios — across Python, TypeScript, Go, and Rust. Here is exactly where each tool excels and where it falls short.