Rollup 4.0 vs esbuild 0.21: Library Bundler Speed Test

Modern JavaScript library development relies heavily on bundlers to package source code into distributable formats. Two of the most popular options for library bundling are Rollup, a long-standing favorite for ES module-first workflows, and esbuild, a newer, Go-based bundler known for extreme speed. With Rollup 4.0 bringing major performance improvements and esbuild 0.21 introducing new library-focused features, we ran a series of speed tests to see how they stack up.

Test Setup

We designed the benchmark to mimic real-world library development scenarios. All tests were run on a machine with an 8-core Intel i7-12700K CPU, 32GB DDR4 RAM, and Node.js 20.11.0.…