Reference
What is VP9?
VP9 is an open video codec developed by Google and widely used for web video, especially in WebM and online streaming. It predates AV1 and remains common in existing browser and video-platform libraries.
VP9 is: a video codec. WebM is: a container commonly used to carry VP9. The two names should not be treated as synonyms.
VP9 profiles, bit depth and chroma
| Profile | Bit depth | Chroma |
|---|---|---|
| 0 | 8-bit | 4:2:0 |
| 1 | 8-bit | 4:2:2 or 4:4:4 |
| 2 | 10 or 12-bit | 4:2:0 |
| 3 | 10 or 12-bit | 4:2:2 or 4:4:4 |
Where VP9 appears
WebM is the most familiar VP9 container. VP-family video can also be bound into ISO Base Media File Format/MP4-family files under defined sample-entry rules, though device support varies.
VP9 vs AV1
AV1 is the newer open codec and generally targets better compression efficiency, but VP9 decoding is mature and widespread. Existing online libraries contain huge amounts of VP9 video, so it remains operationally relevant.
Common confusion
vp09 is commonly seen as a codec string/identifier in browser or MP4 contexts. It is not a separate codec from VP9.