How to Add a YouTube Video to a Playlist Directly from the YouTube Search Results

Go to YouTube on your computer.

Open a web browser and go to https://www.youtube.com. Sign in with your username and password if you're not already signed in.

Search for a video.

Type your search terms and press ↵ Enter or ⏎ Return. A list of search results will appear.

Click the "Show more" menu.

Hover your mouse cursor over a video and click ⋮. You won't see this three-dot icon until you hover your cursor over the video. The icon will appear on the far-right side.

Click "Save to Playlist."

This option appears on the "Show more" menu. A list of your playlists will appear.

Select one or more playlists.

Click the square next to each playlist you want to add the video to. The video will be added to all playlists you select here.