Speed and Performance

What makes each JavaScript bundler fast or slow, and where it typically sits in that spectrum.

Webpack

Generally the slowest of this group on large projects — its pure-JavaScript, single-threaded core and heavy plugin pipeline make both cold builds and rebuilds noticeably slower than newer alternatives.

Rollup

Reasonably fast for its pure-JS implementation, though like webpack it doesn’t take advantage of multi-core parallelism the way Go/Rust-based tools do.

Parcel

Faster than webpack for typical projects thanks to its Rust-backed transform layer and built-in caching, though generally not as fast as esbuild, Turbopack, or Rspack on very large codebases.

esbuild

Often 10-100x faster than JavaScript-based bundlers for equivalent work, largely due to Go’s native compilation and aggressive parallelism across CPU cores.

Vite

Fast in development regardless of project size, since it avoids bundling entirely by serving native ESM; production build speed depends on whichever bundler it delegates to (historically Rollup, increasingly Rolldown).

Turbopack

Benchmarked by the Next.js team at multiple times faster than webpack for incremental builds, with its caching model specifically designed to keep large applications fast as they grow.

Rspack

Sits between Vite and Turbopack on most benchmarks, generally winning on raw production build time thanks to its Rust core, while remaining close to webpack’s memory usage due to a similarly complex feature set.

Bun

Very fast for typical projects, comparable in spirit to esbuild, though its plugin ecosystem and edge-case coverage are less mature than more established bundlers.

Rolldown

Aims to close the performance gap between JavaScript-based Rollup and Go/Rust-based tools like esbuild, while preserving Rollup’s plugin compatibility and output characteristics.