HTML5 video
Support for HTML5 video has been steadily increasing. In June 2013, Netflix added support for HTML5 video. In January 2015, YouTube switched to using HTML5 video instead of Flash by default. In December 2015, Facebook switched from Flash to HTML5 for all video content.
YouTube
On January 27, 2015, YouTube announced that HTML5 would be the default playback method on supported browsers. YouTube used to employ Adobe Dynamic Streaming for Flash, but with the switch to HTML5 video now streams video using Dynamic Adaptive Streaming over HTTP (MPEG-DASH), an adaptive bit-rate HTTP-based streaming solution optimizing the bitrate and quality for the available network.