All about OGX files

OGX is a file extension for the OGG container, which was introduced by the Xiph.Org Foundation in 2008. Originally, only .ogg was used as the file extension for all content in the Ogg container, which eventually led to problems. Early hardware players and software expected .ogg files to contain only Vorbis audio (Ogg/Vorbis). Anyone who named videos in the Theora codec or other codecs with .ogg experienced incompatibilities. Therefore, the Xiph.Org Foundation introduced the new extensions .oga for audio, .ogv for video and .ogx for multiplexed Ogg. Multiplexing in this context means that multiple streams/tracks are contained in the .ogx file.

In practice, however, I often find that .ogx is generally used for regular audio files with the OPUS or Vorbis codec. file-converter-online.com treats these files like normal .ogg files and offers the corresponding conversion options. I have written an article on the creation of OGX files on Android here: Why Android 15 Downloads .ogg Files as .ogg.ogx – A MIME Type Analysis.

The .ogg formats in the (theoretical) overview:

According to RFC 5334, the following rules apply to file extensions:

Sources

RFC 5334 – "Ogg Media Types" (IETF, 2008): https://www.rfc-editor.org/rfc/rfc5334
RFC 3533 – "The Ogg Encapsulation Format Version 0": https://www.rfc-editor.org/rfc/rfc3533
Xiph.Org Wiki – MIME Types and File Extensions: https://wiki.xiph.org/MIME_Types_and_File_Extensions

Last updated on 12. March 2026 by Sören with the experience of more than 127,912,138 converted files since 2013.