es-toolkit is a JavaScript utility library that provides modern implementations of common functions with strong TypeScript support and minimal bundle size.
The library addresses the need for performant utility functions in modern JavaScript environments. It replaces traditional approaches by offering implementations optimized for contemporary runtimes, achieving significantly faster execution than comparable libraries while maintaining a small footprint through tree-shaking support. The tool provides everyday utilities such as debounce, delay, chunk, sum, and pick, alongside type guards like isNotNil, all with built-in TypeScript annotations.
Developers should consider es-toolkit if they want to reduce bundle size without sacrificing performance or type safety. It suits projects that prioritize both speed and minimal dependencies. The library includes a compatibility layer available as es-toolkit/compat that allows seamless replacement of Lodash, making migration straightforward for existing codebases. Projects already using Lodash can adopt the compatibility layer incrementally or switch entirely to the native API for better performance.
The project maintains comprehensive test coverage and receives active development with contributions welcomed from the community. The tool is used by established open-source projects including Storybook, Recharts, ink, and CKEditor, indicating production-grade reliability. The project provides AI integration through Agent Skills for tools like Claude Code, Cursor, and Copilot, extending its utility beyond traditional library usage.
