Used to be a great add on a decade ago. It's absolute junk now and has trouble downloading and detecting.

I have serious suspicion that this addon causes memory leak and CPU overload at youtube live streams. One of the firefox.exe processes took full CPU core and a couple of GBs of RAM. When I turned off VDH addon, the values went back to normal. This issue can be mistakenly credited to firefox itself, so please, if you have similar symptomps, try to turn off all addons.

Promts me to install another program in order to proceed downloading a video. I reported this to mozilla.

useless crap, don't waste your time.

Adiciona un WaterMark y además solicita la instalación de un plug-in adicional

kræver ekstra program installation.

You have to install a separate installer. They put a watermark and you must pay it to remove the watermark.

It's a converter, not a downloader. As such, it's much slower and resource intensive than it needs to be. It also watermarks the video.

下载youtube试了好多次，每次都是卡在汇总中。不好使！

Doesn't allow downloading without also installing a dangerous external EXE.

Why do I need a companion app?

don't waste your time, it doesn't work on mac

This requires a "companion app" that looks shady

Bad video compression and worst of all: A big-ass QR-code in the corner of the screen unless you pay up. Could have been upfront about it, I would not have wasted my time.