You will need to install a user script manager extension to install this script.
CTRL+, = Rewind media by 1/30th second CTRL+. = Fast forward media by 1/30th second CTRL+SHIFT+/ = Next frame (when paused; Firefox only) SHIFT+LEFT = Rewind media by 30 seconds SHIFT+RIGHT = Fast forward media by 30 seconds CTRL+LEFT = Rewind media by 1 minute CTRL+RIGHT = Fast forward media by 1 minute CTRL+SHIFT+LEFT = Rewind media by 5 minutes CTRL+SHIFT+RIGHT = Fast forward media by 5 minutes CTRL+/ = Fast forward media by 1.5 minutes 0 to 9 = Seek media to 0%, 10%, 20%,...90% SHIFT+0 to SHIFT+9 = Seek media to 5%, 15%, 25%,...95% CTRL+1 to CTRL+5 = Change audio volume to 20%, 40%, 60$, 80%, 100% CTRL+[ = Decrease media speed by 0.2x (by default) CTRL+] = Increase media speed by 0.2x (by default) CTRL+; = Reset media speed CTRL+' = Change custom media speed CTRL+\ = Change unit of media speed increment/decrement
For Widescreen Video Viewport:
CTRL+6 = Zoom ultra widescreen content to remove top+bottom borders, but also remove left+right content a bit. CTRL+7 = Change video aspect ratio for letterbox content. Fix 4:3 letterbox content stretched to widescreen format. CTRL+8 = Change video aspect ratio for TV content. Fix 4:3 TV content stretched to widescreen format.
For 4:3 TV Video Viewport:
CTRL+SHIFT+6 = Change video aspect ratio for ultra widescreen content. Fix ultra widescreen content compressed into 4:3 TV format. CTRL+SHIFT+7 = Zoom 4:3 letterbox content to remove half of top+bottom borders, but also remove left+right content a little. This can also be used to half-zoom ultra widescreen content on widescreen viewport. i.e. half-zoom of CTRL+6. CTRL+SHIFT+8 = Change video aspect ratio for widescreen content. Fix widescreen content compressed into 4:3 TV format.
For Any Video Viewport:
CTRL+9 = Reset video aspect ratio
Some shortcuts won't work on non US keyboards. Non US keyboard users will need to manually edit the keys in the script.
In YouTube, if the video speed is below 0.25x or above 2x, the YouTube setting display will be capped to 0.1x or 2x.
Web browser video speeds: Firefox = 0.25 to 5.0; Chrome = 0.1 to 16.0.