#output.polyfill

• Type: 'entry' | 'usage' | 'off'
• Default: 'off'

Controls the polyfill injection mode.

See Polyfill Mode for more details.

#Install core-js

When you enable polyfill injection, make sure core-js v3 is installed in your project, which is a popular polyfill library for JavaScript.

npm add core-js

yarn add core-js

pnpm add core-js

bun add core-js

deno add npm:core-js

#Optional value

#usage

With output.polyfill set to 'usage', Rsbuild checks the APIs used in each file compiled by SWC and injects the polyfills needed by the target browsers. Files not compiled by SWC are not checked. Use source.include to compile additional files.

export default {
  output: {
    polyfill: 'usage',
  },
};

#entry

With output.polyfill set to 'entry', Rsbuild injects polyfills in each entry file. The injected core-js polyfills are selected for the target browsers, regardless of which APIs your code uses. This can increase bundle size.

export default {
  output: {
    polyfill: 'entry',
  },
};

#off

With output.polyfill set to 'off', Rsbuild doesn't inject polyfills. You need to handle code compatibility yourself.

export default {
  output: {
    polyfill: 'off',
  },
};

#Version history