GridMaster with Pixel Ruler and Crop

Measure any webpage with rulers, guides, custom grids, snapping, element inspection, and precise PNG crops.

I built GridMaster for those moments when a page looks slightly off and you need a real answer instead of another guess. It puts practical layout tools directly on the page, so you can check spacing, alignment, and dimensions without jumping between apps. Drag guides from the top or side ruler, place them at an exact position, and adjust their color or thickness. Turn on a square grid or build a column layout with your own spacing and gutters. When you need more than pixels, switch the rulers and measurements to inches, centimeters, millimeters, or points. It also handles the parts that usually slow the job down: snapping a guide to a real page edge, checking an element's exact size and position, and capturing one specific area as a PNG. What you can do: * Drag horizontal and vertical guides from the rulers * Enter exact guide positions and adjust line thickness * Lock, duplicate, recolor, or remove individual guides * Switch between px, in, cm, mm, and pt * Use square grids or custom column grids * Snap guides and measurements to page elements * Inspect element dimensions and position * Draw measurement areas and copy their dimensions * Download or copy a selected area as a PNG * Hide the toolbar or rulers while leaving your guides in place * Undo changes and use keyboard shortcuts for common actions I use it for quick layout checks, but it is just as useful for designers, front-end developers, QA testers, marketers, and anyone who needs a reliable measurement or a clean crop from a webpage. Privacy is straightforward: your settings stay in Chrome, and GridMaster does not send your page data, screenshots, or browsing history to an outside service. Click the GridMaster icon whenever you need the tools. Click it again when you are done.