YouTube Extension for all Browsers since 2012. Now Open-Source & preparing to run on all video sites. Enhances Youtube & every video player (soon) to give users more control over all aspects of content discovery, playback, view & the Youtube site. You can add any functional button/s to the player. And increase focus: You can schedule more meaningful/matching content to watch. You can adjust the permanent sizes of Videos & player-controls. And for example have the video description expanded by default. You can hide related videos and avoid any other distractions. Make whole channels & playlists play in reverse or chronologically. Lock video quality to be high at home or low on the go. - And many other options. We created the Extension for you carefully to make sure all existing YouTube features work properly and without issues. We care about UX (user experience) and made our options really easy & pretty. We don't need to collect your data but only give you a tool that runs offline to modify your view locally only. The extension can also sometimes enable faster video playback, so that together we saved tons of CPU (electricity, CO2), depending your GPU. (Through h.264) - This situation is about to repeat: VP8, VP9 & AV1 ).
Just a few more things you can do with ImprovedTube are: Fixed playback speed (SpeedListening), disable up-next autoplay, settting the video size to fit the whole tab, fixed volume, auto-pause, hiding any distractions ("Lecture-/Teacher-/Presentation-mode", to save time and make Youtube more fun / clean to and use for example in presentation (We have no specific parent-mode yet) and much more!
Faster than reading about all of the options, you can get the extension and see for yourself what 'ImprovedTube' can do for you. Many of our users love it so much, they can not use YouTube without it.

(ImprovedTube is free to download and use. With over 480,000 active users & a nearly perfect star rating,
we are set to stay the best through transparent development on Github.)
In the past 9 years we have seen several other projects try something similar for some years but give up again.
Are you a developer? Please join us (on Github ) - through volunteering you can reach so much more than in almost every job
- Or, if you already worked on any YouTube Features, we will be so happy to review & link them below

Other selected / curated YouTube extensions

The following got some smart, unique or cool features. They are compatible with ImprovedTube (and respected users at the time of our review):
Video Playback features:
Frame by Frame (Precision for all web Videos)
Youtube Speed Slider precise, below Player & Looper (& unBlob or VideoDownloadHelper)
Youtube Text features:
YCS Youtube comment Search - search through ALL comments, comments with timemark (and transcript.)
Invideo for Youtube - Enabling you to search inside of Youtube Videos
TurboNote - efficiently take and share time-stamped notes
Subtitles For YouTube - drag and drop .SRT files
AlienTube for YouTube (add Reddit comments, or: SnooTube),
Youtube Music features:
Transpose - Pitch - Loop for videos
dance or play-along drums, guitar, ... :
Save Youtube Bandwitdh (/data costs):
Audio Only Youtube (alternatively set low resolution in ImprovedTube)
Youtube-site Features:
FasTube - Prevents reloading YouTube for every video.
Hotkeys: Streamkeys (open-source), Ratings Preview for YouTube, Controls for Youtube, Youtube Subscription(Collection) Manager, Video Deck for YouTube, YouTweak, Better YouTube Watch History, Subscriptions Grid For YouTube, Youtube Watched classic view, Youtube Refined.
Youtube-site visuals: Color Changer for YouTube (we got a great Youtube theme customization now too), Stylish - Custom themes for any website Fun/Memes for Youtube: Nyan Cat Progress Bar for YouTube, Herp Derp for YouTube)
Content creator features ("Youtubers / Vloggers"):
Pro Mode for YouTube Video Editor, Tags for YouTub, vidIQ Vision for YouTube, TubeBuddy for YouTube

2. With ImprovedTube you don't need the following (usually):
Similar features:
Looper for Youtube, except we have no "range-slider" yet),
Magic Actions for YouTube, except for video filters (fun) and country location proxy;
Bandwidth Saver, Hide YouTube Comments, YouTube Adblocker, Youtube Adblock, Adblock for Youtube, Floating for YouTube, Window Expander For YouTube, Youtube Playback Speed Control, Video Speed Controller, h264ify (open-source), Enhancer for YouTube, Iridium for YouTube (open-source), DF Tube (Distraction Free for YouTube); Dark Skin; Dark Youtube Theme; Turn Off the Lights, except if you want to control dark-mode with webcam Automatic 4K/HD for Youtube, AutoHD for YouTube, AutoHD Plus for YouTube, Your Quality for YouTube, Reverse Playlist, Theater Mode for YouTube, Auto Replay for YouTube, Listen on Repeat, Youtube Video Repeater, Popout for YouTube. YouClever / 'You Clever videocombine speed up bloggers'.(asking to change privacy settings now). We did not througly review similar extensions and of course some can be incompatible to eachother sometimes. However that's no real issue. You can just test compatibility and tell us if you identify any glitches ever. (Besides that many popular extensions / apps require permissions for alerts, ads and datamining browsing activity/history)
3. Popular but outdated: - are you still using any of the following? - Let's invite their developers! : SmartVideo For Youtube ( Dash Playback, YouTube Advanced Control; YouTubeCenter, YouTube Flash Video Player, Flash-HTML5 for YouTube, Disable Youtube HTML5 Player, Flash Player for YouTube.)

Previously: July 28 2020: Sorry for the outage!

(/ "*"-permission) We were shocked, that our testing version was sent to everybody. Chrome Web Store actually got an option to test a new Version with 3% of users only - however this does not seem to work and update everybody untested...
So all it takes to confuse half of you is a click in webstore. (this will not happen again). With all of you the next years will be even more motivating and worth getting more perfectionist every day. (if you like to help testing though (rarely) please join our BETA)