Ogg
Also known as: .ogg file, Ogg Vorbis, Ogg container
Ogg is a free, open container format that wraps compressed audio — most often Vorbis or Opus. The `.ogg` extension tells you the wrapper, not the exact codec inside, so two Ogg files can hold quite different audio. The contents are usually lossy, so files stay small.
- A container, usually holding Vorbis or Opus
- Typically lossy, so files stay small
- Open and royalty-free, common on the web
A container, not a codec
A container is a wrapper that holds one or more media streams plus metadata; the codec is the method used to compress the audio inside. Ogg is the container, and what it carries is typically Vorbis (an older MP3-style lossy codec) or Opus (a newer, more efficient one).
Because both common payloads are lossy, Ogg files are generally compact — comparable to MP3 or smaller for the same quality. A lossless codec (FLAC) can also live in Ogg, in which case the file is much larger.
Compatibility and converting
Ogg is open and royalty-free, so it is popular in games, web audio, and open-source software. Modern browsers and players read it, but Apple devices and some editing apps may not open it cleanly.
When an app refuses an `.ogg` file, the simplest fix is to convert it to MP3, which plays almost everywhere.