If you're moving from one podcast host to another, you won't lose subscribers if you do a 301 redirect from your old RSS feed to your new RSS feed.
For example, on Reddit, a user asked:
I am wanting to switch podcast hosting services. When I switch, will all the podcast directories upload new episodes when I put the link to my new RSS feed into the RSS feed redirect of the old host? For instance, after I switch services and upload a new episode via the new hosting service, will Spotify, iHeartRadio, Google Podcasts, Stitcher etc have the new episode listed?
Here's how to switch your host without losing subscribers on Apple Podcasts, iTunes, Spotify, Google Podcasts, and Stitcher.
Podcast players (like Apple Podcasts and Spotify) pull your podcast's information from your RSS feed. A 301 redirect lets these apps know where your new feed is hosted.
On most hosting platforms, doing a 301 redirect from your old RSS to your new RSS is easy:
On Simplecast: go to "Podcast settings" and scroll to the bottom until you see "Advanced settings."
On Libsyn: go to your Dashboard and click on "Destinations." Click "Edit" for the "Libsyn Classic Feed." Click "Advanced Options" at the bottom of the page. Paste in your new Transistor feed URL in the "Redirect Feed to this Web Address" input box.
On Buzzsprout: go to "My Profile" and then to the "Cancel/Redirect Podcast" tab. You should see an option that says "Redirect Your Podcast Feed."
On Transistor: go to "Settings," and scroll down to "Advanced Settings." There, you'll see "Permanent Redirect (301) of your RSS Feed to another URL."
Once you've set a 301 Permanent Redirect to your new feed, Apple Podcasts and other directories will pick up the change automatically so your audience won't even notice.
(Want to migrate your podcast to Transistor from Simplecast, Libsyn, or Buzzsprout? Read this guide).
Marco Arment, the creator of Overcast, notes the importance of Apple Podcasts:
The iTunes Store’s Podcasts directory is the only one that matters, and being listed there is essential for podcasts to be easily found when searching in most apps.
Apple should follow the 301 redirect to your new podcast feed, but you can also update your feed address on Apple's Podcast Connect. Just log in, find your show, and paste in your new feed URL.
While most apps and directories (like Overcast, Pocket Casts, Castro, Breaker) will scrape Apple's podcast directory, there are a few other "walled gardens" that you'll need to update manually.
After you've redirected your old RSS feed to your new feed, it's best to wait two weeks before you delete your old hosting account. Also, it can take 24-48 hours for Apple to propagate your new feed on their platform. Be patient!