DJ Pangburn explains why WebM has taken off among the Cinemagraphs and High Quality Gifs crowd:

4chan, infamous birthplace of Anonymous, and renowned the world over for its free-for-all image boards, announced yesterday that it added support for WebM to host animated images that are higher quality than GIFs in a smaller file size. At this point, you might be asking what is WebM and how is it better than the GIF format, the current king of easily-embeddable, looping animations? Here's a quick rundown on the WebM technology, the way of the future for compressed video.

WebM is an open-source audio-video codec for HTML5 video sponsored by Google, but originally built around technologies developed by On2, Xiph, and Matroska. "The WebM format combines the [On2's] VP8 video codec, the Matroska container, and the Vorbis audio codec developed by Xiph into a high-quality, open, unencumbered format for video delivery on the Web," wrote Xiph's Chris Montgomery back in 2010, shortly after that year's Google I/O Conference, when the format was announced. 

Initially WebM was lauded for being a royalty-free alternative to the H.264 codec, which powers everything from online videos to Blu-Ray discs. But it also has an interesting advantage as compared to other video formats: WebM videos can be easily coded to autoplay and endlessly loop without an additional video player, which makes them a potential competitor to the GIF, which currently reigns supreme for easily-shared, easily-embedded animations.

Its advantages over GIF include "superior image quality, support for more than 256 colors, and reduced file size," as 4chan's Moot (Chris Poole) noted. "Its main disadvantage is browser compatibility, however 86% of 4chan’s visits come from browsers that include full or partial support for WebM, and plug-ins are available for those that don’t (like Internet Explorer and Safari)." WebM animations are still more like a video than an image file, which means they're trickier to manipulate and upload, as evidenced 4chan's WebM encoding guide. Currently, Chrome, Firefox, and Opera offer browser support for WebM, while Safari and Internet explorer require third party plugins.

GIFs are primarily useful for their versatile, looping imagery, which can be anything from artful and absurd to Idiocracy-level dumb. And part of the GIF charm is the often delicious crappiness of the animation. Using a looping WebM video seems to offer distinct advantage: it looks and runs much better and smoother than GIF, while offering audio (which 4chan disallowed for a number of reasons), and takes less bandwidth. None of this guarantees it will surpass the GIF in usage, and four years into its life, it's nowhere close.

However, 4chan's commitment to the technology could prove influential, though they might have erred in banning audio and capping clip length, which would further differentiate it from GIF. In fact, many 4chan users have already expressed their discontent on the encoding guide thread, with one user writing, "Yay, so instead of making audio an option in the inline extension and having it off by default you've chosen to bring in a new era of silent WebM's... Thanks moot, now 90% of future WebM's I download will be shit mute ones."

WebM could also find an aggressive community of users on Reddit, especially in places like /r/highqualitygifs and /r/cinemagraphs, which could help trigger a critical mass toward mainstream acceptance. But, if WebM fans truly want to surpass GIF, someone's going to have to make them easier to use—which could be as easy as Imgur adding WebM support.

Go Imgur go!

WebM looping animations are embedded like any other HTML5 video, which makes them more difficult to work with than a gif, which only needs IMG embeds. They do look nice, though.

I like them and we on PandaWhale will eventually support embedding of them.