Browser & Node.js Support

es-toolkit/compat works as published in any environment that supports ES2015:

Environment	Minimum version
Chrome	51+
Edge	15+
Firefox	54+
Safari	10+
iOS Safari	10+
Node.js	6+

No transpilation and no polyfills are needed. You can use es-toolkit/compat as-is, without any extra bundler configuration.

This is different from the main es-toolkit library, which requires Chrome 98, Safari 15.4, or Node.js 20.12 and later out of the box. See Browser Support for details.

This applies to es-toolkit/compat and its per-function entry points (es-toolkit/compat/*). Every other entry point, such as es-toolkit or es-toolkit/array, follows the requirements of the main library.

Why compat supports older environments

es-toolkit/compat exists to help you migrate away from lodash. Code that uses lodash often still runs in old environments, such as older Node.js servers or old browsers. So that you can switch from lodash to es-toolkit/compat without changing your build configuration, es-toolkit/compat works in those older environments as published.

How it is verified

Support for these environments is verified on every change, in two ways.

• Statically with ESLint: eslint-plugin-es-x restricts the code of es-toolkit/compat to ES2015 syntax and built-ins (optional chaining and ?? are allowed because the build converts them to older syntax), and eslint-plugin-compat checks it against a Node.js 6 target.
• On a real Node.js 6 in CI: every es-toolkit/compat/* entry point of the built package is loaded, and every @example of the compat functions is executed.