SpotiFork is a web app allows you to merge playlists to one playlist without any registration!
- Go to SpotiFork.
- Click the green button to login with Spotify.
- Import the playlist you want to merge playlists on.
- Click edit button on the right side of playlist.
- Paste the playlist link you want to merge from.
- After adding a new source playlist you will see tracks with buttons next to them
- Click on the button if you want to add song or not
If you made any changes without using SpotiFork don't forget to refresh relevant thing.