Full device scan
One guided pass over everything on a desk: screen, keyboard, mouse, speakers, microphone and webcam. Open it on a phone and it swaps to the touchscreen and sensor checks instead. A few minutes, and a list at the end of anything worth chasing.
0 of 10 checked. Progress is kept in this browser, so you can stop and come back.
1. Display resolution
Nothing to do — your display is read automatically.
Looks right when: The resolution should match your screen's native panel. A 1440p or 4K monitor showing 1920 x 1080 is running scaled and will look soft.
Reading your display…
Every check here is the full tool, not a cut-down version — open Screen Resolution Test on its own if you want the background on what it measures.
When this is worth running
A new or rebuilt machine is the obvious case. Faults that are trivial to fix on day one get expensive later: a monitor with dead pixels is returnable in the first week and an annoyance for years after, and a mouse that has started double clicking is usually still inside its warranty when the symptom first appears.
It is also worth a pass after moving a desk, since crossed speaker cables and a half-seated monitor cable are the two most common things to survive a move unnoticed. And it is a fast way to check a second-hand machine before you hand over money, because most of what goes wrong with a used desktop shows up in these ten checks.
The settings-related results tend to be the valuable ones. A high refresh rate monitor running at 60 Hz and a 4K panel running scaled are both extremely common, both cost you something every day, and neither announces itself.
How the scan works
Each step runs the full tool from its own page, not a cut-down version, so anything you find here you can dig into with the same test and its explanation. Some checks are measured for you; the rest ask you to say whether what you saw or heard looked right, because nothing in a browser can tell you a speaker sounded wrong.
The scan picks its checks from the device you are on. A touch-primary phone or tablet gets the touchscreen, sensor and vibration checks; a desktop or laptop gets keyboard, mouse and monitor. A touchscreen laptop counts as a desktop, since it still has a pointer and a keyboard. You can switch profiles by hand at any time, and the choice is remembered.
Progress is kept per profile in your browser, so you can stop after the screen checks, plug in the rest of the desk, and come back to where you left off. Nothing is uploaded, no account is involved, and the microphone and camera are only touched on the steps that need them.