The developer of this extremely powerful plug-ins has done a great job of ensuring you can download any vids. A lot of user documentation but I do fumble still with the options. All-in-all, great work!

Awesome add on!!! Be sure to add the HLS plugin for this to be an extremely versatile tool.
Plugin links:
https://addons.mozilla.org/en-US/firefox/addon/hls-downloader/

https://github.com/puemos/hls-downloader

Perhaps one of the best addons for firefox... Inevitable

good tool

これまで使っていたダウンロードソフトの中で一番で素晴らしいソフトです

Realmente es un complemento muy completo, se agradece a todos los desarrolladores que han hecho posible el uso de esta muy útil herramienta,si pudiera le daba 7 estrellas

I've found Video Download Helper very helpful in my studies. I see they need money and I'd like to send some but it would have to be a cheque in $Can and I need their mailing address.
Mike Walton

If you're looking for an app that's simple & easy to use, this software works great for downloading videos for personal use. Quality of downloaded videos is good.

THIS IS THE BEST DOWNLOADER I HAVE HAD, EASY TO USE AND EFFICIENT.

BEST PROGRAM OF ITS TYPE THAT IVE USED

this add-on is awesome.

当我发现这个插件的时候，空气仿佛充满了氧气，让人兴奋。

Used to get the job done satisfying, but not anymore. The video lags when I click around now and the quality is subpar. Much worse than before, and I assume it's intentional. What a shame

希望能增加一個”僅下載，不做任何處理的選項“。//Hope to have an option like "download only, no any process"

I've had a lot of luck with this problem--able to grab most videos I'm after. Definitely recommend.