YouTube Auto Theater Mode

WHAT IT DOES

YouTube Auto Theater Mode is a browser extension that automatically scans the current YouTube page for video player and theater mode toggle controls. It detects the video player and theater mode button by examining class names, IDs, and data attributes. The extension adds a floating auto theater button (🎬) next to the video player, providing quick access to theater mode controls. Clicking the button opens a panel where you can enable or disable auto theater mode, set your default view mode (Theater, Default, or Fullscreen), toggle theater mode automatically when a video loads, and store preferences locally. The panel displays the current video title, theater mode status, and settings toggles. You can set global preferences that apply to all videos, or override them with video-specific preferences. The extension maintains a theater mode preferences database with settings history, notes, and tags for each video. The main panel shows saved preferences for the current and recent videos. All data is stored locally in your browser using GM_setValue, ensuring your preferences persist across page reloads and browser sessions. This helps users who prefer watching YouTube videos in theater mode to automatically enable it without manually clicking the button every time, providing a more immersive viewing experience.

WHERE IT RUNS

This extension runs on any YouTube page that displays video player and theater mode toggle controls – including YouTube watch pages and any page with YouTube video content. The extension intelligently adapts to different page structures and supports a wide range of common YouTube display patterns. No manual configuration is required per site; the extension automatically detects video elements using a flexible pattern matching system. This makes it ideal for users who prefer watching videos in theater mode.

HOW TO USE

Simply install the extension and navigate to any YouTube video page. The extension automatically detects the video and shows an auto theater button (🎬) next to the video player. Click the button to open the theater mode panel. The panel shows the video title and current theater mode status. Toggle "Enable Auto Theater" to turn the feature on or off. Toggle "Enable on video load" to automatically enable theater mode when a video starts playing. Select your default view mode from the dropdown (Theater Mode, Default View, or Fullscreen). For video-specific preferences, choose "Theater Mode for this video", "Default for this video", or "Use global setting" to override the default for individual videos. A floating button (🎬) appears in the bottom-right corner of the page – click this to open the panel from anywhere. Use the notes section to add notes about viewing preferences or screen size. The panel also shows saved preferences for the current video and recent videos. Use the "Clear All Preferences" button to remove all tracking data when needed.

ONE TECHNICAL SECTION – WHY IT WORKS

The extension uses DOM detection and event simulation to control YouTube's theater mode. The theater mode toggle button is detected using a comprehensive set of CSS selectors targeting aria-label attributes (Theater mode), class names (.ytp-size-button, .ytp-theater-button), and player control patterns. The current theater mode state is determined by checking the player container's class list for "theater" or by inspecting the player container's style width. When toggling theater mode, the extension simulates a click on the theater button using the native click() method. The extension also detects when theater mode changes via YouTube's UI and updates the indicator accordingly. The auto-on-load feature uses a setTimeout to ensure the player is fully loaded before applying the theater mode toggle. Each video's theater mode preference is stored in the local database with video ID, title, mode selection, and timestamps. A MutationObserver detects dynamic content updates and re-scans only when the video player changes, balancing real-time accuracy with system performance.

THE PANEL – DRAG / PER-SITE POSITION / SNAP / COLLAPSE / RESIZE / ESCAPE

The auto theater panel includes a draggable title bar, allowing you to position it anywhere on screen for convenient access during video watching. The extension remembers your preferred position per website, so the panel opens in the same location each time you return to that domain. The panel supports snap-to-edge behavior – when dragged near screen edges, it gently snaps into place for a tidy workspace layout. You can collapse the panel down to just its title bar by clicking the collapse button, keeping it accessible without taking up screen space. The settings and history are contained within a scrollable body, ensuring all content remains accessible even on smaller screens. Pressing the Escape key closes the panel instantly, returning you to your video viewing workflow.

PLEASE NOTE

This extension requires the free BotGentz extension to be installed and enabled, as it relies on BotGentz's userscript injection and GM_* API shims for cross-browser compatibility. Websites frequently update their HTML structures and class names, which may cause theater mode detection to break temporarily – we actively maintain the matching patterns and release updates regularly. The extension stores all theater mode preferences, notes, and history exclusively in your local browser storage (GM_setValue); no data is ever transmitted to any external server or third party. The extension does not read, modify, or interfere with any YouTube content, videos, or functionality beyond the theater mode toggle – it operates on the page content and stores only metadata (video IDs, titles, mode preferences, and notes) that you explicitly create. You are responsible for backing up your preference data if you switch browsers or clear your storage. Use this tool responsibly and in accordance with YouTube's Terms of Service.