ScreenSync is a free Chrome add-on designed for frontend developers to preview websites across multiple screen sizes simultaneously. It eliminates the need to toggle between different viewport sizes, allowing users to see mobile, tablet, laptop, and desktop views side by side within a single tab. This tool is particularly beneficial for testing responsive designs and ensuring consistent layouts across various devices.

With features such as synced scrolling, custom viewport sizes, and an auto-refresh mode, ScreenSync enhances the workflow for developers. Users can easily zoom in or out, fit the screen, and utilize keyboard shortcuts for quick adjustments. The tool operates directly within Chrome, making it lightweight and convenient without requiring additional downloads. ScreenSync is ideal for freelancers, teams, and anyone involved in CSS development who needs to verify responsiveness efficiently.