Detect Supported Video Formats with JavaScript
Over the past few years we've been seeing new audio, video, and image formats take shape to challenge the legacy formats that we've used since the web's inception. This is a great development as we have more processing power and better compression algorithms have been developed, leading to faster load times and rendering. Hooray for speed!
The problem: as with every other features added to the browser, some browsers get media format support faster than others, and some browsers refuse to support given formats. Simply put: we now need to do feature detection on media, something we've not traditionally had to do. A while back I posted about how you can detect WEBP support in the browser and now I'd like to show you how to detect supported video formats -- it's easier than you think!
HTMLVideoElement.prototype.canPlayType
canPlayType is the secret to detecting video format support in the browser. To use this method you must first create a <video> element instance:
const video = document.createElement('video');
You then call canPlayType, passing in the format's MIME type and additional details as needed:
video.canPlayType('video/webm; codecs="vp8, vorbis"'); // "probably"
There are three possible results from canPlayType:
"probably" : The media type appears to be playable"maybe": Cannot tell if the media type is playable without playing it"": The media type is not playable
Format Detection Function
Modernizr includes a small function to detect video format support; I've taken a moment to take that logic and create my own function for general purpose use without Modernizr:
function supportsVideoType(type) {
// Allow user to create shortcuts, i.e. just "webm"
const formats = {
ogg: 'video/ogg; codecs="theora"',
h264: 'video/mp4; codecs="avc1.42E01E"',
webm: 'video/webm; codecs="vp8, vorbis"',
vp9: 'video/webm; codecs="vp9"',
hls: 'application/x-mpegURL; codecs="avc1.42E01E"'
};
const video = document.createElement('video');
return video.canPlayType(formats[type] || type);
}
// Usage
if(supportsVideoType('webm') === "probably") {
// Set the video to webm
}
else {
// Set the video to mpeg or mp4
}
I use feature detection function efficiency to only create one element and simply return the result if called more than once. Using this function today, Chrome reports the following:
The canPlayType method allowed you to feature detect the best compression and supported formats and server them to your users, thus making the most of your browser capabilities. Get aggressive with your media formats to make your site as quick as possible!
![Serving Fonts from CDN]()
For maximum performance, we all know we must put our assets on CDN (another domain). Along with those assets are custom web fonts. Unfortunately custom web fonts via CDN (or any cross-domain font request) don't work in Firefox or Internet Explorer (correctly so, by spec) though...
![6 Things You Didn’t Know About Firefox OS]()
Firefox OS is all over the tech news and for good reason: Mozilla's finally given web developers the platform that they need to create apps the way they've been creating them for years -- with CSS, HTML, and JavaScript. Firefox OS has been rapidly improving...
![CSS calc]()
CSS is a complete conundrum; we all appreciate CSS because of its simplicity but always yearn for the language to do just a bit more. CSS has evolved to accommodate placeholders, animations, and even click events. One problem we always thought...
![Web Audio API]()
The Web Audio API allows developers to load and decode audio on demand using JavaScript. The more I evaluate awesome games for Firefox OS TVs, the more I get to learn about these APIs that I normally wouldn't touch. The following is a very basic introduction to the WebAudio API...
Thank you for this article and info, but I am sorry, this is insane. WTF MAYBE, PROBABLY means??? Why not TRUE, FALSE, null or whatever similar?
hls returns false everywhere, except Edge. But works everywhere except IE…
This is a great tip! Does anyone know what the proper MIME type would be for a .mov file with HEVC/h.265 encoding for safari?
Am I missing something?
function supportsVideoType(type) { let video; // <-- this is a local variable // Allow user to create shortcuts, i.e. just "webm" let formats = { ogg: 'video/ogg; codecs="theora"', h264: 'video/mp4; codecs="avc1.42E01E"', webm: 'video/webm; codecs="vp8, vorbis"', vp9: 'video/webm; codecs="vp9"', hls: 'application/x-mpegURL; codecs="avc1.42E01E"' }; if(!video) { // <--videowill always beundefined, so!videowill always be true video = document.createElement('video') } return video.canPlayType(formats[type] || type); }