White · #FFFFFF Press F for Fullscreen

Cycles solid colors, grayscale and primaries in fullscreen. Tap where you see a defect; we’ll diagnose it after. Esc exits.

Screen Info

Resolution —

Refresh rate —

Pixel ratio —

Browser zoom —

Color depth —

Aspect ratio —

Color Picker

White #FFFFFF

Shortcuts

←→Switch test color
FEnter fullscreen
EscExit fullscreen

Custom Color

Free · No install · Nothing uploaded

Monitor Test — Free Online Display Testing

Test your monitor, laptop or phone screen right in the browser. Check for dead pixels, backlight bleed, ghosting, refresh rate and color — then mark and diagnose anything that looks wrong.

How the test works

Every tool here is built around the same honest loop. Nothing pretends to detect defects automatically — your browser can’t know what your physical panel actually does, so instead we help you see, mark and interpret problems yourself.

1Test

Fullscreen solid colors reveal defects a busy desktop hides.

2Mark

Tap anywhere you see something wrong. A thin box records the spot.

3Diagnose

A few plain questions sort dead, stuck and bleed apart.

4Fix

Stuck pixels get a non-contact color-cycling fix attempt.

5Retest

Re-check the same spots to confirm whether the fix worked.

All display tests

Dead Pixel Test Full-screen color cycling with a mark → diagnose → fix → retest loop. Touch Screen Test Draw, multi-touch tracking, and a dead-zone grid scan. Backlight Bleed Test Full-black test with a 60s dark-adaptation timer and zone guide. Refresh Rate Test Measure real Hz from frame timing over a 5-second sample. OLED Screen Test Black level → burn-in → uniformity → color → banding, one pass. Resolution Checker Instant resolution, DPR, PPI and aspect ratio readout. Ghosting Test Adjustable-speed moving objects to reveal trailing and smear. Monitor Calibration Tool Seven-step visual calibration: brightness → gamma → color balance. Colorimeter Guide What a colorimeter is, ΔE explained, and who should buy one. Stuck Pixel Fixer Draggable high-frequency noise square with a countdown timer.

Solid color screens

White Screen Black Screen Gray Screen Red Screen Green Screen Blue Screen

Testing a monitor in your browser

A good monitor test does not need any software. Because your browser can paint the whole screen a single color and read back basic display metrics, a browser-based monitor tester can cover the checks most people actually need: dead and stuck pixels, backlight bleed, motion ghosting, refresh rate, resolution and rough color uniformity. That is exactly what this site does, and it runs the same on a desktop monitor, a laptop panel or a phone.

If you are testing a monitor you just bought or are about to sell, start with the Dead Pixel Test — it is the check most likely to turn up a real, returnable fault. On a PC monitor with a high refresh panel, the Refresh Rate Test and Ghosting Test confirm you are actually getting the motion clarity you paid for. For a laptop or phone screen, the Backlight Bleed Test and a quick pass of the white and black screens catch the most common panel problems.

What this monitor test screen checks

Dead & stuck pixels — solid color fields across the whole screen.
Backlight bleed & IPS glow — a full-black field with a dark-adaptation timer.
Refresh rate — measured from real frame timing, compared to reported Hz.
Ghosting & response — moving objects at adjustable speed.
Resolution, DPR & color depth — read live from your device.
Color & grayscale — calibration charts and a full-color sweep.

Frequently asked questions

Can a browser really detect dead pixels?

It can show you the colors that make dead pixels visible, but it cannot detect them for you — no web page can read the state of a physical pixel. This test helps you find and classify defects; it never claims a false “we found N dead pixels.”

Is anything uploaded or saved?

No. Every test runs entirely on your device. The few things we remember during a session — your marks and diagnoses — stay in your browser tab and are never sent to a server.

Do I need to install anything?

No. Everything works in a normal browser tab. For the most accurate results, use native resolution, 100% zoom, and full brightness in a dark room.