CSS Peek: Element Inspector is a free Chrome add-on designed for web developers and designers. It provides a straightforward way to inspect elements on any webpage and visualize their CSS box model, which includes margin, border, padding, and content. This tool is particularly useful for debugging layouts and understanding spacing quickly, making it an essential addition to any web development toolkit.

One of the standout features of CSS Peek is its intuitive interface that allows users to click on any webpage element to reveal a visual box model diagram. This diagram is color-coded for easy interpretation, displaying the precise pixel values of each layer directly in the overlay. The extension is lightweight and user-friendly, ensuring that it can be seamlessly integrated into any web browsing experience without impacting performance.