ZenCast doesn’t restrict what kind of audio files you can upload, and we don’t do any conversions or change your episode file behind the scenes. What you upload is what we publish.

However... not all audio file types are compatible with all platforms and devices, so it's best to use file types and settings that will enable the most people to download and listen to your podcast.


We recommend the following file attributes for the best compatibility and listening experience:

  • MP3

  • Mono encoded at 96-128 kbps, 44.1 kHz

  • Or Stereo encoded at 128-256 kbps, 44.1kHz

  • CBR (Constant Bitrate)


The above works as a basic outline, but if you're technically minded and want to know more details, it can be worth checking out Apple Podcast's audio file requirements.


Why MP3 for podcasts?

Researching online, you'll find plenty of discussions about what file formats give superior sound quality for the size of the file. All of these debates aside, MP3 is the most widely compatible audio file type across multiple devices and platforms, and that should be regarded as a top priority when you're trying to reach as many listeners as possible. It's no good having the world's best audio quality if large parts of your potential audience can't play the file on their device.


Podcast audio file size limits

There is no size limit on the audio files you can upload to ZenCast, although we recommend keeping each upload/episode under 100 MB to make it easier on listeners using a mobile connection. In most cases, each listener downloads the same size file that you upload to ZenCast, so users on a slower connection won't appreciate having to wait for gigabytes of audio to fill up their device storage.

If you need to swap out the audio of an episode you already uploaded in the wrong format, check out our help article on how to replace episode audio files.


Still confused about audio settings? Talk to us in the chat bubble!