Fullifier is an Safari Web Extension that lets you play every HTML5 (thats about every web video) video in the native macOS fullscreen video player.
With this you get native scrubbing, the various skip functions and more you love about the system video player. Never struggle with annoying video players on the web again.

If you have an HTML5 video playing on any website like Youtube just press the Fullifier Button in Safari's address bar to enable native fullscreen for this video.

With this extension you can even use the system fullscreen player on sites that hide the native video controls or use own (most of the times worse) video controls.

Usage:
1. Open Safari
2. Open Safari Preferences
3. Go to Extensions
4. Enable Fullifier
5. Press the Fullifier button on a website with a video