Indexing is the act of scanning a channel or playlist (aka: source) for new media.
Normal indexing uses yt-dlp
to scan the entire source on your specified frequency, but it's very slow for large sources. This is the most accurate way to find uploaded media with the tradeoff being that pairing a large source that's indexed frequently will result in you spending most of your time indexing. Only so many indexing operations can be running at the same time so this can impact your other source's ability to index.
Fast indexing takes a different approach. It still does an initial scan the slow way but after that it uses a secondary mechanism (either RSS or YouTube's API) to frequently check for new videos. This has the potential to be hundreds of times faster, but it can miss videos if the uploader un-privates an old video or uploads dozens of videos in the space of a few minutes.
RSS is used by default but you should enable the YouTube API if you want the best version of fast indexing. This isn't needed for most users but it provides the fastest and most reliable media updates.
Here is some documentation
on how to get your API key which you can add in the
settings
page.
To make up for this limitation, a normal index is still run monthly to catch any videos that were missed by fast indexing. Fast indexing overrides the normal index frequency.
TL;DR
In general:
Fast indexing is great if any of these apply:
- The source is large channel and uploads frequently
- You want to download a source's new content as soon as possible
Consider not using fast indexing if any of these apply:
- The source is a playlist
- The source has under 200 videos
- The source rarely uploads
- You don't mind if it takes longer for new content to be picked up