a YouTube Extension since 2012. Now Open-Source, available for all Browsers & planning to do so much more. Enhances Youtube ( + potentially every video player), to give you more control over all aspects of content discovery; playback; look & feel of the YouTube sites. You can add features & buttons to the player. And increase focus (schedule more meaningful / matching content to watch.) You can always show the video description and transcript but hide related videos and avoid other distractions & popular content. You can adjust the permanent sizes of Videos & player-controls or lock the video quality to be high or low. You can watch channels & playlists in reverse or chronologically. - And many other options. We created the Extension for you carefully and make sure all YouTube features work properly with no side effects. We care about UX (user-experience) and try to make our options really easy & pretty. And we don't need to collect your data but only give you a tool that runs offline to modify your view locally only.
Sometimes we can even fix bugs on YouTube pages or speed up the video-player (DOM, VP8 VP9 AV1 h.264), so that together we saved tons of time/CPU/electricity)
- a few more things you can do are: Permanent playback speed (Speed-Listening), disabling up-next autoplay, setting the video size to fit the whole tab, fixed volume, auto-pause when switching tabs, auto-pip, hiding any distration, element or ads (a.k.a "Lecture-/Teacher-/Presentation-mode", to save time and make Youtube more fun / clean. (no parent-mode) - and much more!
- Much 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 anymore".

(ImprovedTube is free to download and use. With over 500 000 active users & a nearly perfect star rating (inspite all YouTube changes), we are set to become or stay the best through transparent development on Github. (In the past 10 years we have seen several other projects try something similar for some years but give up again.)
Are you a developer? Please join us! (through volunteering you can reach so much more than in almost every job.) - Or, if you already worked on any YouTube Features, we may be happy to review & link them below.

We volunteers work for you on many wishes & bugs:

All issues

discord.gg/aHpjrhf (new)

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, ... : GitHub.com/ktsn/mirror-tube/tree/master/js
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
Similar features: (With ImprovedTube you don't need the following usually):
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)
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!

(/ "*.youtube.com"-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 took was a click in webstore. (Yet 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 you can join our GitHub or Beta version at least)