Yesterday, I put an end to my HEY World experiment. After making the call, I wanted to keep my content and migrate it to Substack. So, I tried the Substack RSS feed import feature, but it wasn’t working. As shown in the following screenshot, the error wasn’t explicit enough to pinpoint the cause of the problem.

Substack's RSS feed import couldn't see my HEY World content

I had 23 posts to import, which was not a big deal, but I preferred not to move my content manually. Trying different variations of the URL didn’t help. Substack wouldn’t detect any feeds from HEY World. Here is my solution.

HEY World uses ATOM RSS feed format. I thought Substack couldn’t parse those. The idea was to transform the ATOM RSS feed into something else. After googling for a solution, I remembered about RSSMix (this service is no longer available and FeedPress is way better). This free web service enables merging many feeds into one. I use it to merge all my personal RSS feeds into a single one to build a publishing timeline. It’s pretty cool1. For my HEY World content migration, I took the ATOM RSS feed with another one and merged the content2. The end result is another feed, but this time in XML format. I went to Substack again, and sure enough, the resulting feed could be imported. After the import was completed, all I had to do was delete posts from the second feed content which wasn’t part of HEY World3. Simple as that.

Update #1: 2022-05-22 : Since the publication of this article, I moved (again) my newsletter to Ghost. Update #2: 2024-06-15 : Replace RSSmix with FeedPress as the former is no longer available

  1. I think I should write about it in a different post. ↩︎

  2. RSSMix requires at least two RSS feeds to work. I chose one of mine with little content associated with it. ↩︎

  3. The one thing I would have liked from Substack was a way to select each post individually before hitting the Import button. ↩︎