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Multiple Browsers ​

You can build an extension for any combination of browser and manifest verison. Different browsers and manifest versions support different APIs and entrypoints, so be sure to check that your extension functions as expected for each target.

Separate build targets are written to their own output directories:

<rootDir>
└─ .output
   ├─ chrome-mv3
   ├─ firefox-mv2
   ├─ edge-mv3
   └─ ...

Target Browser ​

To build for a specific browser, pass the -b --browser flag from the CLI:


wxt --browser firefox
wxt build --browser firefox

By default, it will build for chrome. When excluding the manifest version flags, it will default to the commonly accepted manifest version for that browser.

BrowserDefault Manifest Version
chrome3
firefox2
safari2
edge3
Any other string3

TIP

To configure which browser is opened when running dev mode via wxt -b <browser>, see the Development docs docs.

Target Manifest Version ​

To build for a specific manifest version, pass either the --mv2 flag or --mv3 flag from the CLI.

sh
wxt --mv2
wxt build --mv2

When the -b --browser flag is not passed, it defaults to chrome. So here, we're targetting MV2 for Chrome.

Customizing Entrypoints ​

There are several ways to customize entrypoint definitions per browser.

First, you can use either the include or exclude option to include or exclude the entrypoint from specific browsers. Here are some examples

ts
export default defineBackground({
  // Only include a background script when targeting chrome
  include: ['chrome'],
});
ts
export default defineContentScript({
  // Do not add this content script to the manifest when targeting firefox
  exclude: ['firefox'],
});
html
<!-- entrypoints/options.html -->
<html>
  <head>
    <!-- Don't include the options page for safari -->
    <meta name="manifest.exclude" content="['safari']" />
  </head>
</html>

Second, you can change individual options per-browser:

ts
export default defineBackground({
  persistent: {
    // Use a non-persistent background script for just safari
    safari: false,
  },
});
ts
export default defineContentScript({
  matches: {
    // Run the content script on different pages for each browser
    chrome: ['*://*.google.com/*'],
    firefox: ['*://*.duckduckgo.com/*'],
    edge: ['*://*.bing.com/*'],
  },
});

WARNING

Only defineBackground and defineContentScript support per-browser options right now.