1ClickDLInstall 1ClickDL and its extension.
On Mac or Windows. Three steps to your first video.
1. Install the app
From your computer, choose Mac or Windows in the Download section. If the links are unavailable, only use an installer sent to you by the developer.
2. Choose a folder
Open 1ClickDL. Select your project folder, paste a link and click Download.
3. Use the extension
In the app, open Settings → Extension → Connect the extension. On a YouTube video page, click its icon, then Download. The video appears in Downloads.
More than one video?
Choose Add to queue while browsing. Then start the queue from the app.
Install the preview extension
Open chrome://extensions in Chrome or Comet. Turn on Developer mode, then Load unpacked and choose the folder sent by the developer.
Network interruption?
Keep the .part file and resume from the app. Do not rename it to .mp4.