Does Castos alter the media files after upload?

No. We believe the file that you upload should be exactly the same file that your audience listens to. We don't modify the metadata, bitrate, or file format of your podcast files when (or after) they're uploaded to our platform.

Supported audio episode media files: MP3 and M4A

Supported video episode media files: MP4

We generally recommend a bitrate of 128kbps as it provides a nice middle ground between high fidelity and reasonable file size for most audio episodes.