Used Laptop Check
A guided pass-or-problem run through every check on a used laptop, with a report to copy or print.
Device, sensor and browser tests
See what your browser knows about your screen, device and web features, and test a phone's motion sensors and vibration.
All device tools
Device Info
See what your browser reports about your device, screen, language and time zone, and copy it.
Screen Resolution Test
See your screen resolution, viewport, device pixel ratio and aspect ratio, and how they relate.
Screen DPI Test
Estimate your screen's pixel density in PPI from its diagonal, and check the browser's nominal inch.
Browser Test
See your browser name, version and user agent, and which web features your browser supports.
WebGL Test
Check that WebGL and WebGL 2 work, see the renderer your browser reports, and watch it render.
Gyroscope Test
Read a phone’s accelerometer, gyroscope and compass live, with a bubble level and a gravity check.
Vibration Test
Send short buzzes, long buzzes and patterns to check the vibration motor of an Android phone.
What these tools show and test
These pages read what your browser reports: the screen resolution and viewport, the device pixel ratio, supported web features and graphics details. They help when a site looks wrong, when you need your exact screen size, or when a web app says your browser is not supported.
Two of them check hardware on a phone or tablet. The Gyroscope Test shows live motion, orientation and compass readings, and the Vibration Test buzzes the vibration motor in Android browsers. No iPhone browser can vibrate, and many computers have no motion sensors.
Browsers round or hide some values on purpose to protect privacy, and extensions can change others, so treat every value as what the browser reports rather than a fact read from the hardware. Sensor readings are the browser's processed values, not a calibration.
Buying a second-hand laptop? The Used Laptop Check walks through every test in order and turns your answers into a report you can copy or print.
Which test do I need?
| If you notice | Try |
|---|---|
| You are about to buy a used laptop | Used Laptop Check, Device Info |
| You need your screen resolution or window size | Screen Resolution Test |
| Text or images look blurry, or too large | Screen Resolution Test, Screen DPI Test |
| A site says your browser is not supported | Browser Test, Device Info |
| 3D content or browser games do not load | WebGL Test |
| Support asks which device and browser you use | Device Info |
| Auto-rotate, tilt controls or the compass do not respond | Gyroscope Test, Device Info |
| The phone does not vibrate | Vibration Test |
Before you start
- Values come from browser APIs. Some are rounded or hidden on purpose for privacy.
- Screen resolution, browser viewport and physical pixels are three different sizes; the pages explain how they relate.
- Browser zoom changes several of these numbers. Reset it to 100 percent for a clean reading.
- Motion sensors and vibration need a phone or tablet; many computers have neither.
Frequently asked questions
What is my screen resolution?
Open the Screen Resolution Test. It shows your screen size in CSS pixels, the device pixel ratio, and the physical resolution those two give. With display scaling on, the CSS size is smaller than the native resolution of the panel.
Why do websites see a different resolution from my display settings?
Display scaling. At 150 percent, a 2560 by 1440 screen reports about 1707 by 960 CSS pixels with a pixel ratio of 1.5. Multiply the two to get the physical resolution back.
Can a website tell my exact device model?
Usually not. Browsers share general information such as the operating system, browser and screen size, and many hide details like the exact model or graphics card name.
Can a website test my phone's sensors or vibration?
Partly. The Gyroscope Test shows the motion and orientation readings your browser receives (iPhone asks for permission first), and the Vibration Test can buzz the motor in Android browsers. No website can calibrate a sensor or measure vibration strength.
Guides
- How to check a used phone before you buy itBefore you pay, make sure the seller has removed their account: an Activation Locked iPhone, or an Android phone still tied to a Google Account, is not worth buying. Then check battery health and the repair history, and test the screen, touch, speakers, microphone and cameras in the phone’s own browser.