Although both OGG Vorbis and MP3 are lossy audio formats, there are some obvious differences between them, which can be summed up as follows:
OGG Vorbis is fully open, non-proprietary and royalty-free to all with no strings attached, while MP3 is originally patented. However, MP3's patent has expired and thus is as free as OGG Vorbis.
2. Quality and File Size
With the same bitrate, OGG Vorbis will perform a better quality with smaller size than MP3.
MP3 compresses digital data at a constant bit rate, while OGG Vorbis is inherently variable-bitrate (VBR).
4. Popularity and Compatibility
There is no doubt that MP3 is very widely supported in general use and familiar with everyone. Although OGG Vorbis owns outstanding performances, it does not be widely accepted as a standard, and some applications don’t support files with the .ogg extension. Therefore, in many cases we need to convert OGG to MP3.