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CYS is a free Firefox add-on that downloads videos in 3GP, WebM, FLV, MP4, HD, Full HD, 3D, and 4K formats (includes DASH formats 480p/1080p, etc). Convert audio track from videos to MP3, or save audio track in native format (Ogg Vorbis, AAC/M4A, MP3). Also saves video page, comments pages and statistics to one folder. Check the latest version here.



If you find CYS to be helpful, please consider supporting us on Patreon, thanks.








*The latest FFmpeg version is needed for muxing DASH video (480p/1080p) and audio. Please


.update your FFmpeg here.


-Portable Firefox users, you can set up FFmpeg in your profile folder, see FAQ under FFmpeg




Downloading Videos:


Download videos in various formats:




MP3 Converter:


Convert audio track from video to MP3 or WAV, or save audio track in native format (Ogg Vorbis,


AAC/M4A, MP3). Enable MP3 Converter in Options> General tab. In addition to the audio formats in the


main list, you can also manually extract the native audio track from any video using the "Save Audio Track


As" options in the submenu (AAC/M4A set in Options).



Save video, video page, and comments pages to one folder:


..1.Hover over the format you wish to download and select "Save Complete Page" from the







..2.Name the project, select the download location, and choose how many comments pages to save:





-With the folder list open, you can double click the "Save in" button to switch from history to custom






..3.Click Ok