Auto HD4k8k for YouTube is a Firefox extension designed to optimize your video playback experience on YouTube. This subscription-based tool allows users to select their preferred video resolution, ranging from 144p up to 8k, and set it as the default option for all videos. With a user-friendly interface, the extension enables seamless switching between resolutions, ensuring that viewers can easily enjoy their content in the quality they desire without manual adjustments each time.

The extension features a lightweight design that does not compromise on performance, making it incredibly fast and efficient. Users can choose from a variety of formats and can revert to YouTube's automatic quality selection if preferred. Additionally, the ability to sync settings across multiple devices enhances convenience, allowing for a personalized viewing experience on any connected PC.