Fixing “webkitSpeechRecognition is not defined” in Firefox

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Why Doesn’t Firefox Support webkitSpeechRecognition?

If you’re encountering the “webkitSpeechRecognition is not defined” error in Firefox or Firefox Developer Edition, but everything works fine in Google Chrome, you’re not alone. This happens because webkitSpeechRecognition is a proprietary API that is only supported in Chrome and Chromium-based browsers (such as Edge, Opera, and Brave).

Mozilla has not implemented Web Speech API for speech recognition (SpeechRecognition). While Chrome provides support via webkitSpeechRecognition, Firefox currently lacks native support for this feature.

How to Fix It (Alternatives & Workarounds)

1. Use a Supported Browser

If you want to use webkitSpeechRecognition, you must switch to Google Chrome or a Chromium-based browser. Firefox will not work with this API. You can see a list of supported browsers at this link or in the following image:

SpeechRecognition Browser compatibility

2. Try Using the Standard SpeechRecognition API

Even though Firefox does not support it, you can write a more flexible script by checking for both webkitSpeechRecognition and SpeechRecognition: 

const SpeechRecognition = window.SpeechRecognition || window.webkitSpeechRecognition;
if (SpeechRecognition) {
    const recognition = new SpeechRecognition();
    console.log("SpeechRecognition is available!");
} else {
    console.log("SpeechRecognition is not supported in this browser.");
}

This will ensure compatibility with browsers that support the non-prefixed version of the API. However, Firefox still won’t work unless Mozilla implements speech recognition in the future.

3. Use a Third-Party Speech Recognition API

If you need cross-browser support, consider using a cloud-based speech recognition service instead of relying on webkitSpeechRecognition. Some popular options include:

These services offer better accuracy and support multiple languages, but may require a backend to process the audio.

4. Use WebSockets + Backend for Speech Processing

If you need a real-time speech recognition solution that works across all browsers, you can set up a backend service that processes speech via an API and sends the text results to the client using WebSockets. This requires more setup but ensures compatibility with Firefox, Safari, and Chrome.

Finally, Firefox Developer Edition does not support the Web Speech API for Speech Recognition, which means webkitSpeechRecognition will never work in this browser. The best solution depends on your needs:

  • For Chrome users: Keep using webkitSpeechRecognition.
  • For cross-browser support: Use a third-party API.
  • For full control: Set up your own backend-based speech recognition system.

At this point, unless Mozilla adds native support for SpeechRecognition, Firefox will not support speech-to-text features natively. If you need this feature in your app, consider alternative approaches!

Would you like a guide on setting up Google Cloud Speech-to-Text or an open-source alternative? Let me know in the comments!