Space Spector is a free Chrome extension designed for designers, frontend developers, and QA engineers to visualize spacing gaps and padding on webpages. By simply activating the extension, users can see an overlay of color-coded highlights that indicate every gap and padding value, making it easier to conduct design reviews without the need to access DevTools. The tool is particularly useful for ensuring consistency in design specifications before finalizing web projects.

The extension offers several features, including the ability to show all spacing elements at once, filter by layer, and focus on either horizontal or vertical spacing with one-click modes. Users can also exclude specific elements from the overlay, switch between dark and light mode for better visibility, and experience zero performance impact due to fixed-position overlays. The clear color legend helps users quickly identify different spacing types, making Space Spector an invaluable tool for effective design handoff reviews.