What does this script do?
This script can convert your music playlists between YouTube & Spotify with a single click.
How to use it:
1. Make sure you're signed in to both YouTube and Spotify in your browser.
2. Open the page of the playlist you want to convert.
3. Click the Tampermonkey icon, then under "YouTube / Spotify Playlists Converter" you'll either find YouTube to Spotify or Spotify to YouTube depending on the playlist currently opened, click it to start the conversion.

4. Once done, you can find the playlist in the opposite service under the same name.
Note:
Starting with v1.5, the script does not use any external services to do the conversion (it's all built into the code), if you notice any inaccuracies with the conversion, please share them in the feedback section.