R.I.P. ytmp3.eu, I guess.

good

Edited review: For now, it works well. I will try it out for a while and see how it goes.

用着还可以，就是下完信息都是未知的。不过能听就已经不错了

конвертит но только через сайт. хоть так

Unlike other reviews, I have not run into spam ads/popups. You just have to use the right ad blocker.

Works great for getting around Youtube's recently changed (some time between Dec'19 - Feb '20) format of not allowing other local downloaders to detect any audio formats or video formats besides webm.
Also downloads quickly, with a bunch of options for trimming, volume, bass, treble, speed, album art like the description says (haven't tested it all though).

However, it must open a new tab to a website that pastes the link and then has option only for 128 or 356kbps. I do not see variable bitrate available.
Anyway, it works fairly decent for most basic purposes and editing. Though I wish it had the variable bitrate, and was a local app than a site.

Update: This add-on is amazing! I can adjust the volume to quiet down loud videos & I can make louder for my deaf son! THANK YOU SO MUCH! To the hard working developer for fixing my bugs ASAP! Sometimes the convert button gets stuck so I have to keep a tab open that worked in order to use.

It adds extra stuff after you load the page/extension. It only pops up once, but very annoying. The extention works perfectly. I highly recommend.