Web Development
What is Bundler?
A build tool that resolves module imports and packages source files into optimized assets browsers can load efficiently.
Definition
A bundler walks the import graph from entry points, resolves dependencies from node_modules, and emits optimized output: combined and split JavaScript chunks, hashed filenames for long-term caching, and processed CSS and assets. Webpack dominated for a decade; esbuild (Go) and swc (Rust) then made transformation orders of magnitude faster, powering Vite—which serves native ES modules unbundled in development and bundles with Rollup for production. Turbopack and Rspack continue the Rust trend. Bundlers also orchestrate tree-shaking, code-splitting, and minification, making them the linchpin of frontend performance work.