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@sindresorhus
sindresorhus / esm-package.md
Last active December 10, 2025 13:22
Pure ESM package

Pure ESM package

The package that linked you here is now pure ESM. It cannot be require()'d from CommonJS.

This means you have the following choices:

  1. Use ESM yourself. (preferred)
    Use import foo from 'foo' instead of const foo = require('foo') to import the package. You also need to put "type": "module" in your package.json and more. Follow the below guide.
  2. If the package is used in an async context, you could use await import(…) from CommonJS instead of require(…).
  3. Stay on the existing version of the package until you can move to ESM.
@jakub-g
jakub-g / async-defer-module.md
Last active November 29, 2025 12:46
async scripts, defer scripts, module scripts: explainer, comparison, and gotchas

<script> async, defer, async defer, module, nomodule, src, inline - the cheat sheet

With the addition of ES modules, there's now no fewer than 24 ways to load your JS code: (inline|not inline) x (defer|no defer) x (async|no async) x (type=text/javascript | type=module | nomodule) -- and each of them is subtly different.

This document is a comparison of various ways the <script> tags in HTML are processed depending on the attributes set.

If you ever wondered when to use inline <script async type="module"> and when <script nomodule defer src="...">, you're in the good place!

Note that this article is about <script>s inserted in the HTML; the behavior of <script>s inserted at runtime is slightly different - see Deep dive into the murky waters of script loading by Jake Archibald (2013)