Merges and Validates All CSS is a free Chrome extension designed for web developers and designers who need an efficient way to manage cascading style sheets (CSS). This tool extracts, merges, and validates all CSS from the current webpage, streamlining the process of ensuring compliance with W3C standards. It simplifies the task of handling multiple stylesheets by consolidating them into one, making it easier to identify and resolve duplicates.

The functionality is straightforward: upon activation on the desired page, the extension gathers all CSS used and sends it directly to the W3C CSS Validation Service for compliance checking. Users simply need to click the 'Check' button to verify the validity of their styles. This extension not only saves time but also enhances the quality of web design by ensuring that the CSS meets established standards.