BlockSite is a Firefox browser extension designed to enhance productivity by allowing users to block distracting or harmful websites. It features a straightforward setup for creating block lists, where users can easily add specific sites or pages. Additionally, it offers the capability to redirect users to more positive websites, promoting a more effective work environment. The extension includes bulk blocking of adult content and enables users to control their browsing experience by setting up preferred redirect sites.

This tool also incorporates advanced features such as blocking by keywords, which allows users to filter out unwanted search queries. Parents can utilize the 'Adult related' keyword block to protect children from inappropriate content. Users can customize blocking intervals based on their schedules and switch between blacklists and whitelists. BlockSite also collects anonymous statistics to help improve its services, ensuring user privacy is maintained throughout.