27-06-2021 funcionou. it worked at this time. let see for more years.

Rough around the edges, looking at the colors in the dropdown box, and a bit too minimalist UI, but the current version works nicely. (1.6.27)

Has worked reliably for years until two weeks ago when I downloaded a now-banned video. I can no longer see the download button. Since then, I have tried to use other YouTube download add-ons, but they do not work either, so maybe the problem is on the Mozilla side or YouTube side. I see that there are "Mozilla recommended" add-ons, but they require invasive levels of permissions.

UPDATE: I uninstalled and reinstalled. Now working. (Disable-/re-enable did NOT work).

it is very good

2 choices are available "normal" AND "HD 720P", I don't know why the first video I tested there isn't HD 720p available. But it seems that most of the time 720p is working fine,
thanks for your work !!!

This add-on has worked great off and on. Currently it is not working. Needs an update. Great app when working! Thanx Igor

GOOD

Gave it another try and it indeed working now. Before the download button would not appear. But now it appears and it downloads videos. Changing my review to reflect that it works now.

( 4 Star !!! if problem fix early i will give you 5 star !!!! )
Hello Team i am using this extension from more then 2 to 3 years , and very trusted Extension and never disspointed to me , but now this week if i am trying to downloded any video its correct but size is showing 0 Byte and it says currept or damaged ???
so please fix it as early as possible thanks you ♥ & Support from India

Pros:
1) doesn't ask for a lot of permissions
2) actually recognizes videos
3) actually downloads videos, and gives the user the option of where to save them
4) decent download speeds
5) download button in a logical place
6) allows downloads as MP4 or WEBM

Cons:
1) does not tell you the file size of the video you are trying to download
2) does not tell you the resolution of the video you are trying to download in some cases. Some videos will only say the file format and "Normal", which can apparently be any resolution under 720p.
3) Does not recognize all available resolutions. Very annoying to watch something in 720p or 1080p only to find out that it can only be downloaded in 360p.

Overall this is a very solid add-on imo. i've been looking for hours for a decent youtube downloader and this is one of the few that both works and doesn't stripmine my computer for data. Cons 1 and 2 should be easy fixes.

Con 3 is something most/all of the video downloaders are experiencing right now, so i have to assume it's more of a general problem with firefox or youtube rather than something specific to the add-on. Still hoping it gets fixed soon.

Many thanks to the devs for making a decent product, and i look forward to the next version.

update: 2 years later and this is STILL the best video downloader available. thanks again for making a good product.