BunNode.jsJavaScriptRuntimeToolingPerformance
Bun vs Node.js in 2025: Performance, Tooling, and Compatibility
Why Bun?
Bun is an all-in-one JavaScript runtime with a fast JS engine, built-in bundler, test runner, and package manager. It aims to reduce complexity and improve performance.
Performance Snapshot
- Faster startup and cold-boot times
- High HTTP throughput on simple handlers
- Built-in tooling reduces spawn overhead
Compatibility & Gotchas
Node core module compatibility is strong but not perfect. Native addons and edge libraries may require workarounds. Test your stack carefully before switching.
Tooling Trade-offs
- Bun test and bunx are fast, but CI ecosystems still center on Node
- Package manager differences (bun install) vs npm/pnpm/yarn
- Built-in bundler is great for simple apps; complex builds may still prefer Vite/webpack/RSBuild
Migration Guidance
Start with non-critical services. Validate compatibility (fs, crypto, worker_threads, native modules). Keep Node for production until coverage and monitoring match.
Bottom Line
Bun is compelling for greenfield and internal tooling. Node remains a safe default for complex ecosystems. Many teams will run both.