YouTube High Definition is a browser extension for Firefox designed to automatically play YouTube videos at your preferred resolution. Developed by Baris Derin, it eliminates the need to manually adjust video quality every time you click a new link. Core Features
Auto-Resolution Selection: Forces videos to load in specific resolutions like 4K, 1440p, 1080p, 720p, or lower based on your preference.
External Embedding Support: Applies your high-definition preferences even when watching YouTube videos embedded on third-party sites like Reddit or Facebook.
Audio Optimization: Automatically forces the highest available audio quality for music videos.
Player Controls: Allows you to change the default player size, auto-mute volume levels, or auto-stop video playback. Installation & Troubleshooting
The add-on can be installed directly via the Firefox Add-ons Marketplace.
While it has a 3.8 out of 5-star rating, recent user reviews indicate that frequent changes to YouTube’s internal code sometimes break the extension’s auto-resolution and theater mode features. If you experience buffering or quality locks, toggling the extension off and on or clearing your Firefox cache typically restores functionality. Popular Alternatives
If you encounter compatibility issues, alternative Firefox extensions provide similar or expanded controls:
YouTube in HD (720p, 1080p, 1440p, 2160p): A lightweight option that lets you set a high-quality default while offering a toggle to disable high frame rates (above 30 FPS) if your hardware lags.
Turn Off the Lights: A popular ambient lighting extension that includes a reliable built-in YouTube Auto HD configuration tool in its options menu.
If you are experiencing issues with video playback, tell me: What resolution are you trying to force? Are you getting any error codes or infinite buffering? What version of Firefox are you currently running?
I can provide specific troubleshooting steps or recommend an alternative configuration.
YouTube High Definition – Get this Extension for Firefox (en-US)