is-language-code

Is given string a language code (as per IANA)

Install

This package is pure ESM. If you're not ready yet, install an older version of this program, 3.1.0 (npm i is-language-code@3.1.0).

npm i is-language-code

Quick Take

import { strict as assert } from "assert";

import { isLangCode } from "is-language-code";

assert.deepEqual(isLangCode("de-419-DE"), {
  res: false,
  message: 'Two region subtags, "419" and "de".',
});

assert.deepEqual(isLangCode("sr-Latn"), {
  res: true,
  message: null,
});

Documentation

Please visit codsen.com for a full description of the API. If you’re looking for the Changelog, it’s here. Also, try the GUI playground.

Contributing

To report bugs or request features or assistance, raise an issue on GitHub.

Licence

MIT License

Copyright 2010-2025 Roy Revelt and other contributors