YouTube Loop Segment Marker

WHAT IT DOES

YouTube Loop Segment Marker is a browser extension that automatically scans the current YouTube page for video player and video progress controls. It detects the video player and captures video ID and title. The extension adds a floating loop marker button (🔁) next to the video player, providing quick access to loop controls. Clicking the button opens a panel where you can set loop start and end markers using fine controls, enable or disable looping, adjust markers with numeric inputs or by capturing current video time, and store loop segment history locally. The panel displays the current video title, duration, and loop status. When looping is enabled, the video automatically seeks back to the start marker when it reaches the end marker, creating a seamless loop. The extension maintains a loop segment database per video with segment history, notes, and tags. The main panel shows saved loop segments for the current and recent videos. All data is stored locally in your browser using GM_setValue, ensuring your loop segments and preferences persist across page reloads and browser sessions. This helps musicians, language learners, fitness enthusiasts, students, and anyone who needs to practice or repeat specific parts of a video to mark and loop segments for practice, learning, or repetition.

WHERE IT RUNS

This extension runs on any YouTube page that displays video player and video progress 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 the page URL and video player. This makes it ideal for users who want to loop specific video segments for practice or learning.

HOW TO USE

Simply install the extension and navigate to any YouTube video page. The extension automatically detects the video and shows a loop marker button (🔁) next to the video player. Click the button to open the loop panel. The panel shows the video title, ID, and duration. Use the "Enable Loop" toggle to turn looping on or off. Set the start and end markers using the numeric input fields or click the ⏱️ button to capture the current video time. Click "Apply Loop" to activate the loop – the video will automatically repeat the segment between the start and end markers. Use "Jump to Start" and "Jump to End" to quickly navigate to marker positions. 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 segment content or purpose. The panel also shows saved loop segments for the current video and recent videos. Use the "Clear All Loops" button to remove all tracking data when needed.

ONE TECHNICAL SECTION – WHY IT WORKS

The extension uses the HTML5 Video API to control video playback and implement looping behavior. The video ID is extracted from the page URL using regex pattern matching. The video title is extracted from page metadata using multiple selectors. The loop state is managed in memory with a setInterval that checks the current video time against the end marker every 100ms. When the current time reaches or exceeds the end marker, the extension seeks back to the start marker using the video's currentTime property and ensures the video continues playing. The loop start and end markers are stored in the local database along with video ID, title, notes, and tags. The extension uses numeric input fields with step increments of 0.5 seconds for precise marker adjustment, and the current time capture feature allows users to set markers at exact positions. Each loop segment is saved with timestamps and can be retrieved when revisiting the video. 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 loop segment panel includes a draggable title bar, allowing you to position it anywhere on screen for convenient access during video practice. 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 loop controls 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 video detection to break temporarily – we actively maintain the matching patterns and release updates regularly. The extension stores all loop segment data, 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 player controls – it operates on the page content and stores only metadata (video IDs, titles, loop markers, and notes) that you explicitly create. You are responsible for backing up your loop data if you switch browsers or clear your storage. Use this tool responsibly and in accordance with YouTube's Terms of Service.