VP9 is a royalty-free codec Google released in 2013, developed as an answer to H.265's licensing rather than as a technical leap past it. In practice the two land in a similar place: broadly comparable efficiency, with the edge going either way depending on content and encoder.
Its role now is largely historical but not obsolete. YouTube has served VP9 for years, which means hardware VP9 decoding is present in an enormous installed base of phones, TVs and browsers — including plenty of devices that cannot decode AV1. That makes it the sensible middle rung: better compression than H.264, wider reach than AV1.
Things worth knowing:
- It usually arrives in WebM. VP9 in MP4 is legal and rare, and support for that combination is patchier than either part suggests.
- Its encoder is slow in the same way H.265's is, without AV1's recent round of optimisation work to make up for it.
- It has no meaningful role in file-sharing. Nobody's email client, chat
app or phone gallery expects a
.webm.
For everyday compression — making a clip small enough to send — VP9 is not the codec to reach for. Its natural habitat is a website serving video to browsers, where the container is invisible and the bandwidth saving is real.