Google embarked on the WebM Project in 2010 to develop open source, royalty-free video codecs designed specifically for media on the Web. The second generation codec released by the WebM project, VP9, is currently served by YouTube, and enjoys billions of views per day. Realizing the need for even greater compression efficiency and to cope with the ever-increasing demand for video on the web, Google joined a consortium of major tech companies called the Alliance for Open Media in 2016, and started an ambitious project to develop a next generation royalty-free codec AV1. AV1 was finalized in June 2018, and achieves about an one-third reduction in bandwidth over current generation codecs VP9 and HEVC at a practical hardware and software complexity. This makes AV1 the most advanced video codec available today that is also royalty-free. In this talk, I will provide a technical overview of the most innovative coding tools in AV1, followed by coding results on standard test sets compared against VP9 and HEVC.