When comparing Free Download Manager vs youtube-dl, the Slant community recommends youtube-dl for most people. In the question“What are the best YouTube downloaders?” youtube-dl is ranked 1st while Free Download Manager is ranked 7th. The most important reason people chose youtube-dl is:
It's released to the public domain. Modify at will.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Zip files partial download
Free Download Manager lets you download only the necessary part of a zip file.
Pro Open-source
It's released to the public domain. Modify at will.
Pro Cross-platform
Works on Windows, Mac OS X and other Unix systems like Linux for example.
Pro Ability to download different formats and meta-info
Pro Frequently updated
The developers keep up with YouTube-s meta changes. If the download of a video fails, just update to a new version and it should work.
Pro Works in other places too
Can download from different sources, not just YouTube. Link for supported sites can be found here.
Pro Command-line, and light weight
Cons
Con No Linux Support
Only supports Windows and Mac.
Con No GUI
Command Line driven only. That's what makes it powerful, but less accessible.
Con Was taken down from Github
The RIAA sent a DMCA takedown notice to Github to remove youtube-dl., stating that this is illegal software. Takedown notice has been dissolved since.