The Polymer library is in maintenance mode. For new development, we recommend Lit.

Polymer 3.x works in the latest two versions of all major browsers: Safari 10+, IE 11+, and the evergreen Chrome, Firefox, and Edge.

The Polymer library is a lightweight sugaring layer on top of the Web Components APIs. Some features used by Polymer are not (yet) supported natively in all browsers.

  • For broad web components support, Polymer uses the polyfills from They're lightweight, work well, and provide the feature support Polymer requires.

  • Polymer uses ES6 language features. For browsers that don't support them, Polymer apps need to be compiled to ES5.

  • Polymer uses ES6 modules for packaging. These can be bundled out or transformed to AMD modules for browsers that don't support the required features, which include the import statement, the dynamic import() operator, and the import.meta property.

  • Polymer modules also use Node-style module resolution allowing you to import modules by package name. These specifiers always need to be transformed to paths before being served to browsers.

The following support matrix summarizes the polyfills and transforms required for each browser.

Browser & version Compile? Polyfills? Transform modules? Transform specifiers?
Chrome 66 No No No Yes
Safari 11.1+ No No No Yes
Safari 10+ No Yes Yes Yes
Firefox 60 No Yes No Yes
Firefox 59 No Yes Yes Yes
Edge 17 No Yes No Yes
Edge 16 No Yes Yes Yes
IE 11 Yes Yes Yes Yes
Chrome 41 (Google web crawler) Yes Yes Yes Yes

See the documentation on polyfills and ES6 & modules for more information.