Touch screen test

Press your way across the screen, cell by cell, and find the spots that don't answer.

Touch faults don't affect the whole screen

A digitiser fault — the layer that reads your finger — usually shows up in one band or one corner. The parts you use most keep working, so it goes unnoticed for days until one letter on the left of the keyboard stops registering. Tapping around at random won't find it. Dividing the screen up and pressing every part of it will.

Before you start

Dry your hands. Damp fingers register erratically on a perfectly good screen.
Leave the screen protector on. The state you actually use it in is the state worth testing.
Take off gloves, and pull the case away if it overlaps the edge of the screen.

This check runs as a program inside your browser, so it needs JavaScript. Turn it on in your browser settings and reload. Everything written below still reads fine without it.

The screen is split into twenty cells; press each one and see whether any spot fails to respond. Starting the check covers the whole screen with the grid. Leave your screen protector on — the state you actually use it in is the state to test.

This doesn't look like a touch screen

Run this one on a phone, a tablet, or a touch-capable display. A mouse can fill the cells, but it can't show you multi-touch.

Cells confirmed 0 / 20— not yet
Multi-touch 0 / 2 (if your device supports it)— not yet

Did every cell respond where you pressed?

Press at least one cell before you pick a result.

Results stay on this screen and are not saved.

Not sure what the result means?Dead zones and ghost touch on a touchscreen

How to run it

Press Start fullscreen test; the grid then covers the whole screen.
Press each cell deliberately with a fingertip until all twenty are filled.
If one doesn't take on the first press, go back to that spot repeatedly. Working sometimes and not others is itself worth recording.
Press with two fingers at once to fill the multi-touch check.
Then rotate the device and run it again. A spot that fails in portrait but works in landscape is a hint that the problem is in software, not the glass.

If you find a dead spot

Restart the device first. Touch going unresponsive for software reasons is common enough to rule out before anything else. If the same area still fails after a restart, write down where it is. "Roughly 2cm along the top right edge" is enough. A photo or a short video with your finger on the spot makes it far easier to explain.

Cracks or pressure marks on the glass will usually be treated as damage rather than a fault, and warranty won't apply. With no such marks, take it to the retailer while the return window is still open.

Buying used? Check the accounts and locks first

There's something to check before the touch screen. An account lock cannot be undone once the money has changed hands. However good the screen looks, a locked device is unusable. Press these yourself, on the spot, with the seller watching.

iPhone and iPadOpen Settings and check the name field at the top is empty (signed out). Under Settings → [name] → Find My, "Find My iPhone" must be off, and a freshly reset device must not ask for an Apple account password on the setup screen. That is what a cleared activation lock looks like.
AndroidSettings → Accounts, and check no Google account is still on it. A device reset without removing the account demands the previous owner's password on the next boot (FRP lock).
Screen lock and PINThe lock should be cleared, and you should be able to get into Settings.
Carrier (SIM) lockTry a SIM from another network, and ask the seller whether it was bought abroad.
Lost or stolen statusNote the IMEI (Settings → General → About, or *#06#) and look it up with the carrier or an official checker.

These ticks aren't recorded; they reset when you leave the page. ReturnCheck can't verify any of it for you either. A browser has no way to see it. What it can do is keep the list of the things people forget in front of you while you go through them.

Checking a whole machine?

Run every browser check in one flow instead of opening them one at a time.

Start the full check

Keep going with another checkBacklight bleed test