YouTube Thumbnail Size Fixer is a Firefox extension designed to enhance the user experience on YouTube by allowing customization of video layouts. With this tool, users can adjust the number of video thumbnails displayed per row, ranging from 1 to 12 columns, effectively addressing the issue of oversized thumbnails introduced in a recent layout change. The extension also provides options to hide YouTube Shorts and other unwanted content, along with disabling rollover video playback, making it easier to navigate and discover content without distractions.

This lightweight and fast extension is ideal for desktop users who want to maximize their screen real estate while browsing YouTube. It operates seamlessly across various sections of the platform, including the homepage, subscriptions, and channel pages. Setting it up is straightforward: simply click the extension icon, choose your desired column configuration, and toggle the visibility of Shorts. Enjoy a more efficient and personalized YouTube experience.