es-toolkit is a state-of-the-art JavaScript utility library developed by Toss, one of South Korea's largest fintech companies, as a modern replacement for the widely-used Lodash library. Written entirely in TypeScript with full type annotations, it provides over 100 utility functions for common operations on arrays, objects, strings, numbers, promises, and functions. The library achieves up to 97 percent smaller bundle sizes through native ES module support and complete tree-shaking compatibility, ensuring applications only include the functions they actually use.
Performance benchmarks consistently show es-toolkit running two to three times faster than Lodash across common operations, achieved through modern JavaScript engine optimizations and avoiding legacy compatibility patterns. The library maintains 100 percent test coverage and strict TypeScript typing that catches errors at compile time rather than runtime. For teams migrating from Lodash, the es-toolkit/compat package provides a compatibility layer that matches Lodash's API surface, enabling gradual migration without rewriting existing code.
With nearly 11,000 GitHub stars and adoption by major projects including Storybook, Recharts, ink, and CKEditor, es-toolkit has quickly established itself as the preferred modern alternative to Lodash. It runs across all JavaScript environments including Node.js, browsers, Deno, and Bun without polyfills. The MIT-licensed library receives active maintenance from Toss's engineering team and a growing open-source community, with regular releases adding new utility functions and performance improvements.
