All this thing does when you try to use it is ask you to install an application from another website.

There is no way to download a youtube video with this app, at this time. Each time I attempt to download a video, it says I must install a companion app. When I download Linux distribution companion tar.gz app, and extract to root directory, nothing seems to happen. Unable to get tech support to respond with help.

This extension was my favorite before but its time is out! You get a big QR Code on the video you've downloaded... But there are lots of other extensions without any QR Code or restrictions or any problems! Why use this one???

J'aimais bien ce module à ses débuts, quand il n'y avais pas d'alternative en ligne. C'était léger, rapide, simple et bougrement efficace.
Mais aujourd'hui c'est devenu de la merde. Il faut maintenant obligatoirement passer par l'installation d'un convertisseur useless (alors qu'il a toujours fait sans auparavant) et ralentit CONSIDÉRABLEMENT la navigation YouTube sur Firefox ESR. Regrettable.

It downloads alright, though it does it at some slower speed. So it interferes with the possible downloadspeed somehow.

Secondly, much worse, aggregating sound and the movie (combining of the video file and sound file) takes forever. For a five-and-a-half minute video at 720p it took the plug-in just over 30 minutes! I'm on a I7 3820 @4.1 GHz. FFMPEG is at a 10% CPU load. Such a long aggregation time for this size of a video is not normal.

Thirdly, it didn't finish a few aggregation tasks, I wonder if the browser has to stay open for the duration. Also, imagine if it is a huge file. It would take forever to aggregate.

Setting the download folder fails. Something is wrong with the interface. Sometimes the settings interface closes by itself! What the heck LOL? Clicking on a custom download-folder sometimes works - so it seems - but checking it twice, your option has been deselected again. The settings page needs work.

Finally, the location of the downloaded sound-file (which needs to be combined with the video) isn't known to me yet. It's somewhere. I'd rather like to see everything downloaded in one folder, including files which are just intermediary steps.

All and all, this add-on has so much potential - it also downloads 1080p videos, but the aggregation-time is killing me.

Edit: ARE YOU EFFING KIDDING ME? Now I know why it takes this long to aggregate.
It adds a massive QR code in the top left corner of the video!!!

Also... the video was downloaded in 720p, but the remaining result is is also in 720p... with a bitrate of only 436 kb/s! In other words it looks like a bloody 320p video now, despite the high resolution.

Needless to say I'll uninstall this absolute rubbish in a minute.

They added QR codes at the top left corner.

Add on ruined, uninstalled.

Be warned that you need to install an external windows app to download videos. But that's just the begining: after downloading the video, the extension/app need to "process" it. Why? To put a big QR code watermark into the video *sic*. To do that, your CPU will burn like it was mining crypto. So this extension it's a complete nonsense to me. My advise is to stay away from Video DownloadHelper and use something like youtube-dl instead.

DOWNLOADHELPER worked just fine until a couple of days ago. Now it shows an ERROR page with the comment " we are sorry for that but shit happens"....rather unapropriate for such a worldwide program....!
Any idea why this happened?

Do not trust this addon

Depuis une mise à jour de Firefox, obligation d'installer une application supplémentaire. De plus un QR code est incrusté dans les vidéos téléchargées.

The videos I download & open in MP4 format have jittered, frame-skip playback. Only by using VLC can I watch the corrupt files without jittering.

And for other media I wish to download, there is no MP4 available, but rather other more obscure formats (e.g. MKV?) which also do not open & run properly in standard programmes.

Rubbish. Don't even bother. Shit. Webm shit. Did I say crap.

Pésimo me pide instalar un virus

se cuelga permanente y te exige otros programas

force users to install another software called "Companion App"
seems to be malware

Doesn't work with Facebook.

Used to be very good. Now, it forces to install companion bloatware on Windows.

Trash

I used to use this extension to download picture galleries, but I can't do that anymore. It looks like the dev doesn't really care to fix it, so it's not a worthwhile extension anymore.