What is the Web Speech API and why does Web Captioner require Google Chrome?

The Web Speech API is a JavaScript Web Speech API Specification, published by the Speech API Community Group, that outlines a possible way that browser vendors could eventually make speech recognition and speech synthesis available to in their browsers.

Currently, support for the Web Speech API among browsers is as follows:

Browser Web Speech API Support
Internet Explorer Not supported
Microsoft Edge Not supported
Mozilla Firefox Under consideration. Currently only supports speech synthesis.
Google Chrome Supported
Safari Not supported
Opera Not supported
iOS Safari Not supported
Chrome for iOS Not supported
Chrome for Android Supported, but buggy.

Why does Web Captioner require Google Chrome?

Web Captioner uses Google Chrome's implementation of the Web Speech API for quick, accurate speech recognition. Google Chrome is the only browser that currently implements the Web Speech API. Because I believe Web Captioner will be used mostly in environments where users have control over their browser choice (instead of a restricted enterprise environment, for example), and because Google Chrome is a modern browser with wide adoption, I’ve decided to focus my development efforts on making Web Captioner work great in Google Chrome.

Furthermore, if other browsers eventually implement this API, there is no guarantee that the speech-to-text engine they use will be as accurate as the one Google Chrome uses. They may, for example, use the same speech-to-text engine provided natively by the operating system the browser is running on.