Youtube video downloader browser extension

Step 1: Click this link to download the "tampermonkey" extension

At this time, the extension program is not available, you need to perform step 2

Step 2: Click this link to install the "tampermonkey" extension

Click the install button

The effect of the installation is complete

There is this red download button on any YouTube video page, clicking it will jump to the page to download mp3 or mp4.

Firefox Browser
Download the Chrome extension