Import maps

Import maps allows control over what URLs get fetched by JavaScript import statements and import() expressions. Import maps enables polyfilling of and fallback from built-in modules.Import maps also allow bare import specifiers to be mapped to actual URLs.

Import maps enable built-in modules. So far we have avoided speccing and shipping any built-in modules, in large part because they have disadvantages compared to built-in globals. Import maps is an attempt to address these disadvantages. Concretely, while globals can be polyfilled or virtualized without import maps, modules cannot be. See more examples in the explainer, for polyfills and for virtualization.

Documentation

Specification

Editor's draft

Status in Chromium

Blink>HTML>Script


Origin trial (tracking bug) in:

  • Chrome for desktop release 74
  • Chrome for Android release 74
  • Android WebView release 74

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No public signals
  • No public signals
  • No public signals
  • Strongly positive

Owners

Last updated on 2019-03-12