How to publish a podcast on Substack

Substack asks whether the podcast lives inside your existing publication or in its own section. That choice decides who gets emailed every time you publish, and changing it later is awkward, so make it deliberately.

Inside the main publication is right when the audio is the same material in another format, and your whole list should get it. A separate section is right when the podcast is genuinely a different thing, because it lets readers take one and not the other rather than unsubscribing from both.

Substack accepts a finished MP3 or M4A. It has no noise reduction, no levelling and no real editing, so anything wrong with the file when you upload it is wrong in the published episode.

Three things are worth doing to every file before it goes near the upload button. Cut the false starts and the long pause where you checked your notes. Take the room noise out without thinning the voice. Even out the volume, because a listener on headphones on a train will hear every dip.

Keep the unedited original somewhere. You will want it the first time an edit goes wrong.

Show artwork needs to be square and at least 1,400 pixels on each side, and it has to survive being shrunk to a thumbnail the size of a postage stamp. Test it at that size before you commit. Most newsletter logos with a wordmark fail this and the author never notices.

Title each episode for what it is about rather than the date or the episode number. A stranger scrolling a podcast app sees the title and nothing else, and "Issue 47" tells them nothing. Put the guest's name in if there is one.

Write the description for someone who has not read the written version, since a podcast app listener has not.

A free episode goes into the public RSS feed and can be found by anyone in a podcast app. A paid episode goes to paying subscribers through a private feed they add to their own app.

If everything is paid, the public feed is empty and the podcast apps become useless to you as a discovery channel. Most writers who make this work keep a regular free episode as the front door and put the rest behind the wall.

Substack generates the RSS feed and submits it to Apple and Spotify on your behalf, but the first episode can take a day or two to appear and occasionally needs the feed resubmitting. Check it yourself rather than assuming.

Open the show in a real podcast app, not the Substack preview. Play the first thirty seconds and the last thirty. Check the artwork rendered, the description is not truncated mid-sentence, and the audio starts when you expect rather than after four seconds of silence.

If something is wrong, fix it in Substack and let the feed update. Do not create a second show, which is the most common and most annoying mistake to undo.