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Grid Alignment Test

Pixel grid for geometry and projector keystone fixes.

Press F for fullscreen

About Grid Alignment Test

A 40-pixel reference grid plus a centered 3/4 frame. Use it to verify panel-pixel alignment, projector geometry, drawing-tablet calibration, or any time you need an evenly-spaced visual reference. Every grid line is exactly one device pixel wide, so it doubles as a quick HiDPI scaling sanity check.

Projector Keystone and Geometry Correction

Display the grid fullscreen on a projector to check keystone distortion and geometry alignment. A properly aligned projector renders every grid line straight and every square perfectly proportioned. Use the centered 3/4 frame as a reference target — it should be exactly centered on the projected image with equal margins on all sides. Adjust the projector's keystone, lens shift, and zoom until the grid appears undistorted from the viewing position. Event technicians, classroom AV installers, and home theater builders use this grid as the standard alignment reference for projector setup.

Drawing Tablet and Pen Display Calibration

Artists using Wacom, Huion, XP-Pen, or iPad drawing tablets use the alignment grid to verify pen-to-screen mapping accuracy. Display the grid fullscreen, then use your stylus to trace along the grid lines. Any deviation between the pen's tracked position and the visible line indicates a calibration error. Run your tablet's calibration utility and re-test until the pen tracks accurately across the entire surface. Digital illustrators and animators perform this check regularly because calibration drift accumulates over time and affects line precision in professional artwork.

HiDPI Scaling and Pixel Alignment Check

Every grid line in this tool is rendered at exactly one device pixel width, making it a quick sanity check for HiDPI and Retina scaling settings. At the correct scaling factor, lines appear crisp and uniform. At incorrect settings, lines appear blurry or doubled due to anti-aliasing between logical and physical pixels. Developers testing responsive web layouts use the grid to verify that their scaling configuration renders UI elements at the correct physical size. IT administrators use it to confirm that enterprise monitor deployments are configured at the optimal scaling ratio.

How to use it

  1. 01

    Press F to fullscreen

    The grid fills the panel. A correctly scaled display shows 1-pixel lines without anti-alias smear.

  2. 02

    Verify the center frame

    The 3/4 box should be perfectly centered on every monitor — useful as an aim point for projector keystone.

  3. 03

    Download the current view as a PNG

    Click the download icon in the top-right toolbar — it sits between the settings gear and the fullscreen button. We detect your display's physical pixel count (screen resolution × device pixel ratio) and rasterize the current configuration into a Retina-sharp PNG. The file lands in your browser's default downloads folder; to save straight to the Desktop, enable 'Ask where to save each file' in your browser settings. The filename includes the resolution so you can keep multiple variants side by side.

Frequently asked

The shortest path between you and the answer.

Is this tool free?

Yes. Every ScreenTools.co tool is free, with no account, no paywall, and no install.

Does it work on mobile?

Yes. Layouts adapt to phone and tablet screens. Mobile Safari restricts true fullscreen, but the page fills the viewport and you can add the page to your Home Screen for an app-like experience.

Does it work offline?

Once a tool's page has loaded once, the runtime is local. A few tools that fetch fonts or icons need the first hit online; after that, refresh works offline.

Does this collect my data?

No personal data leaves your browser. The site has lightweight, privacy-respecting analytics for aggregate counts (which tool was opened) and nothing else.

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