Monitor Test

How to use

1. Go full screen. Click Full screen so the pattern fills the display from edge to edge with no browser chrome in the way.
2. Step through the patterns. Press the arrow keys or click to move through the solid colors, the gradient, and the grid.
3. Inspect each one. On solid colors hunt for any patch that doesn't match the rest. On black check the corners for bleed. On the grid check that the lines stay straight.

Why test this

A monitor can look perfect on the desktop and still hide faults that only a clean full-field pattern brings out. Solid colors expose uniformity problems: patches that read warmer, cooler, or dimmer than the rest of the panel. A pure black field is the one reliable way to judge backlight bleed, the bright leaks at the edges that can justify a return, and to tell it apart from IPS glow, the soft corner haze that shifts with your viewing angle and is normal. A smooth gradient surfaces banding from a weaker panel or heavy color settings, and a grid checks geometry and sharpness into the corners. Run these before the return window closes, and any time the picture looks off. The patterns tell you whether the fault is the hardware, the cable, or a setting, which is the fastest way to separate a real defect from your eyes playing tricks.

What the results mean

There's no score here. You're the instrument, so what matters is what you see. On each solid color the screen should look even from corner to corner. A tint or a darker patch in one area is uniformity drift, common on large panels but it should stay subtle. On the black field, dim the room and study the edges. A faint glow on IPS that fades as you move your head is normal. Distinct bright clouds or bars that stay put are backlight bleed and a fair reason to exchange a new panel. The gradient should fade in one smooth sweep. Visible steps or stripes mean banding. The grid should stay perfectly straight with crisp lines all the way into the corners. Step through every pattern in full screen, ideally in a dim room, and trust what you see twice over a single glance. Flipping between the black and white fields a few times makes most defects easier to confirm.

FAQ

What should a good monitor look like on these patterns?

Solid colors stay even from corner to corner. Black looks uniformly dark with no bright patches. The gradient fades smoothly with no visible bands, and the grid lines stay dead straight into the corners.

What is backlight bleed?

Light leaking around the edges of an LCD on a black screen. Small amounts are common. Large bright clouds or bars are a defect worth a return. Don't confuse it with IPS glow, the soft corner haze that shifts with your angle and is normal. OLED panels have no backlight, so they show neither.

Why does the gradient show stripes?

Visible bands mean the panel is showing fewer shades than the gradient holds. It's common on 6-bit plus FRC panels and gets worse with heavy contrast or color settings.

Can I run this on a phone or TV?

Yes. It runs on any screen with a browser, including phones, tablets, and TVs. Full-screen behavior varies on iOS, but the patterns still fill most of the view.

Is this monitor test free?

Yes, and there's nothing to install. The patterns render locally in your browser, so no images leave your device and nothing is saved.

Embed the monitor test on your page

Reviewing a monitor or writing a buying guide? Drop the monitor test in so readers scan for backlight bleed and uniformity across solid fills and a grid. One snippet, full-screen ready, and eight test patterns load on the spot.

Want the whole set on your pages? See every tool you can embed →