This extension enables YouTube to default to theater mode for the player, even if you're not logged in. If you prefer the default mode, you can easily switch back by clicking the button in the player or using the "KeyT" shortcut. However, the next time you visit, the player will automatically be in theater mode again. The extension doesn't offer any configurable options; it functions seamlessly. It's important to note that the theater mode activated by the extension is authentic and not achieved through CSS or JS tricks; it uses YouTube's actual theater mode. To use this feature in incognito mode, you must allow the extension to be active in this mode. How does the extension work? The extension employs two methods to ensure the player is in theater mode: 1. It sets the relevant cookie on each visit. 2. It triggers the necessary button press when the player loads. For reporting any bugs, please use the discussion section found at: https://webextension.org/listing/youtube-tools.html?theater