A while ago I built a little app which allowed me to subscribe to YouTube channels using the official RSS feeds, more about that here. One thing that I wish it did was exclude shorts, but it seemed the only way to do that was to use the YT API or use some hack.

Then I happened to come across this post on HackerNews, which pointed out that there is an undocumented URL which contains only full-length videos. It can be derived from the channel URL with a search and replace:

Before: https://www.youtube.com/feeds/videos.xml?channel_id=UC...
After: https://www.youtube.com/feeds/videos.xml?playlist_id=UULF...

Apparently these undocumented URLs were discovered by brute force, and there are more.

I've updated my app to use this new feed, and it works beautifully.