Only Used CSS Validator is a free Chrome extension designed to streamline the CSS validation process for web developers. This tool efficiently extracts the CSS that is actively used on the current webpage and interfaces with the W3C's CSS Validation Service to ensure compliance with established standards. By focusing solely on the CSS in use, it helps developers avoid unnecessary code clutter and enhances overall site performance.

To utilize the extension, users simply activate it on their desired webpage. The tool automatically captures the relevant CSS and inputs it into the W3C validation service. With a single click of the 'Check' button, users can quickly assess the validity of their styles, ensuring their CSS adheres to best practices. This straightforward approach not only simplifies the validation process but also promotes cleaner, more efficient coding.