We support MP3, M4A, and AAC formats at present, with a maximum file size of 400MB.
When exporting podcast audio files, it is important to make sure that the file is in CBR format (fixed bit rate). If you choose VBR format compression, the players may not correctly interpret your podcast's length of time, resulting in a disparity between displayed time and actual time.
CBR format guide for common editing software:
GarageBand
You may use MP3 and AAC to export. CBR format is used by default and no additional steps are required.
Audacity
You may use MP3 and M4A to export.
Enable "Constant" Bit Rate Mode for MP3 outputs.
No additional steps are required for M4A outputs.
Audition
You may use MP3, and AAC to export.
You will need to enable constant bit rate for all these output types.