ニコニコクラシックスタイル is a free browser extension designed for Chrome users, aimed at improving the usability of the Niconico platform. This add-on allows users to revert the layout of video viewing pages, user pages, and personal pages to a more familiar format before the recent redesign. Key features include the ability to disable autoplay for videos, customize the video player size up to 1920x1080, and streamline video detail information to reduce scrolling.

Additionally, the extension enhances user experience by adding previously missing links for video articles and public playlists. Users can also adjust the thumbnail size of new timeline entries and change their profile icon shape from round to square. This tool is particularly beneficial for those who find the updated Niconico interface challenging to navigate.