DISCLAIMER: The extension might no longer be updated on the AMO store as a result of reviewer demands Read more about it here: https://github.com/ParticleCore/Iridium/issues/828 --- The extension has undergone a total refactor Read more about it here: https://github.com/ParticleCore/Iridium/tree/1.0.0 Features highlight:

Play videos automatically
Force max thumbnail resolution
Dark theme control
Turn 60fps off

... that's it for now, but there are definitely more features to come with every future release! Feature list: https://github.com/ParticleCore/Iridium/wiki/Features The extension is only compatible with the new YouTube Material layout Ensure you have the layout enabled here: https://www.youtube.com/new Change logs https://github.com/ParticleCore/Iridium/releases Privacy Policy This extension does not store any data that is not required for the functionality of the extension, this being restricted to the user browser and/or user sync settings if the user has sync enabled. This extension does not send any data outside the necessary data for the functionality of the extension, any data transmission is restricted to the youtube.com domain only. This extension does not collect any data for any use other than for the functionality of the extension. This extension does not collect, transmit or make use of personal information. This extension requires the following permissions to operate:

Storage: Used to store the extension settings
Privacy: Required solely for the purpose of detecting when the user has FirstPartyIsolation enabled to enforce the Dark Theme cookie with success
Cookies: Required solely for the purpose of enforcing the Dark Theme cookie
WebRequest: Required to intercept resource requests within the restricted domain
WebRequestBlocking: Required to modify the intercepted requests and modify the source code of YouTube in order for the features to work
://.youtube.com/*: Domain requirement in order to enforce the Dark Theme cookie when user is running the extension in private mode and/or has FirstPartyIsolation enabled
*://www.youtube.com/*: Sub-domain requirement in order to conduct the Web Request Blocking modifications

Cookie usage The extension may store a cookie under the required domain(s) or otherwise modify an existing one. The algorithm in place has been created to prevent other YouTube experiments from being overwritten since these are all shared within the same cookie value. This cookie usage is in place for the sole purpose of enforcing the Dark Theme on YouTube. Without this cookie the Dark Theme enforcement feature will not work leaving by default the normal behavior set by YouTube or no behavior if the user has a browser configuration that clears cookies on exit or if is navigating in private mode.