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isFirefox()

true when the current environment is Mozilla Firefox — stable, Beta, Developer Edition, Nightly — on any platform, including Firefox for iOS (FxiOS/).

Signature(options?: DetectOptions) => boolean
MatchesFirefox/, FxiOS/ (any platform, any edition)

Matches​

  • Firefox/ — desktop and Android editions.
  • FxiOS/ — Firefox on iOS (which is actually WebKit under the hood, but Mozilla branded).

Example​

import { isFirefox } from 'get-browser';

if (isFirefox()) {
  applyFirefoxOnlyWorkaround();
}

SSR​

isFirefox({
  userAgent: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 14.0; rv:138.0) Gecko/20100101 Firefox/138.0',
});
// → true

See also​