This is the complete display check: a single guided flow that walks your screen through every test that matters, so you don’t have to run them one by one. It’s the fastest way to judge the health of any screen — a new iPhone you’re unboxing, a used iPad you’re about to buy, a refurbished Mac, or an external monitor.
The flow steps through solid colour fields to expose dead and stuck pixels, flat greys to reveal backlight uniformity and OLED retention, smooth gradients to show colour banding, and fine text and line patterns to judge sharpness and focus. Each step tells you what to look for. It runs entirely in your browser on any device, with nothing to install — and links out to our dedicated dead pixel, refresh rate, touch and burn-in tools when you want to dig deeper into one area.
How to use it
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1Prepare the screen
Set brightness high, disable auto-lock, and clean the display so smudges aren’t mistaken for faults.
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2Start the guided flow
Tap “Start full screen test”. Each step shows a test pattern with a short note on what a healthy screen should look like.
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3Advance through the steps
Tap to move forward: solid colours, greys, gradients, then sharpness patterns. Take your time on each — faults are subtle.
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4Finish and dig deeper
At the end you’ll see a summary. If one area looked off, open the matching dedicated tool for a closer, more thorough test.
Why This Test Exists
Screen faults and software faults look identical from the outside. A flickering panel, a column of dead subpixels, a patch that never refreshes — on a device running a beta, the first assumption is always that the beta did it. Usually it did not. This test drives the panel directly from the browser, which takes the operating system almost entirely out of the question.
Getting a Reliable Result
Run it in a dark room at full brightness and give each colour a few seconds. Dead pixels stay black on every colour; stuck pixels hold one colour while the rest change. Dust on the glass moves when you tilt the device; a fault does not. Photograph anything you find — a fault that only appears intermittently is very hard to demonstrate at a service appointment without evidence.
Reading the Outcome
If the same defect appears on this test, in the camera app and on the lock screen, it is the panel. If it appears only inside one app, or only after a specific beta build, it is software — and our troubleshooting guides are the better place to start.
Nothing Leaves Your Device
This tool runs entirely in your browser. There is no upload step, no account, no cookie set for it and no record kept of anything you test — which is a consequence of how it is built rather than a policy you have to trust. It also means it works on any device, on any operating system version, whether or not you are running a beta.
If a test here points at software rather than hardware, that is useful in itself: it means the next step is a beta build or a setting rather than a repair. Our troubleshooting guides cover the common ones, and your device's page sets out what to expect from your specific model on the current release.
Frequently asked questions
What does a full screen test check for?
This flow covers the four things that reveal display faults: solid colours (dead, stuck and hot pixels), flat greys (backlight uniformity and OLED image retention), smooth gradients (colour banding and bit-depth), and fine patterns (sharpness, focus and convergence). Together they give you a complete picture of a screen’s health in a couple of minutes.
Is this the best way to test a screen before buying?
Yes. Running one guided flow means you won’t forget a test, and the on-screen notes tell you exactly what a healthy result looks like. For a used iPhone, iPad or Mac, it surfaces the hidden defects — dead pixels, retention, dead touch zones — that are easy to miss and expensive to discover later.
Does the screen test work on all devices?
Yes. It’s built with a full-viewport overlay and pure web patterns, so it runs identically on iPhone, iPad, Mac and external monitors, in any modern browser. No app or download is required.
What should I do if I find a problem?
Open the dedicated tool for that area — the dead pixel test and fixer, the burn-in test and fixer, the touch screen test, or the refresh rate test — for a deeper, more focused check. Each one gives you more detail and, where possible, a fixer.