Soi Máy

Check a used phone, tablet or laptop right in the browser

Test a used phone, tablet or laptop right in the browser, no app needed: dead pixels, touch, speakers, mic, camera, battery, keyboard, Face ID. Free, with a PDF report.

Check device specsSee the model, operating system, CPU threads, GPU, RAM and screen resolution of a phone or laptop in the browser, and compare them with what the seller claims.Dead pixel, backlight bleed and burn-in testFind dead or stuck pixels, backlight bleed, burn-in and lines on a phone or laptop screen. Eight full-screen colours, free, no app to install.Screen refresh rate test (Hz)Measure the real refresh rate of a phone or laptop screen (60, 90, 120, 144 Hz) and check that motion is smooth. Includes iPhone ProMotion instructions.Touch screen test: dead zones and ghost touchesSwipe to fill a grid of cells and spot dead touch zones or ghost touches on a phone or tablet. Runs full screen, free.Multi-touch testPut several fingers on the screen to see how many touch points a phone or tablet registers at once, and whether the dots follow your fingers.Speaker test: left, right, distortionPlay sound on the left and right speakers separately and sweep 60 Hz to 16 kHz to hear rattling, distortion or a buzzing case. Works on phones and laptops.Microphone test: record and play backCheck a phone or laptop microphone with a live level meter, then record 5 seconds and play it back. Audio never leaves your device.Front camera, rear camera and flash testOpen each front and rear camera of a phone or laptop, see the real resolution, check focus, dust or haze in the lens and turn on the flash. Images never leave your device.Laptop keyboard testPress every key to find dead or stuck keys on a Windows laptop or MacBook. Blocks F5 and F12, with a keyboard-lock mode to test F11, Esc and the Windows key too.Touchpad and mouse testTest a laptop touchpad or mouse: left, right and double click, vertical and horizontal scroll, pinch to zoom, and a cursor that doesn't jump.Sensor and vibration testCheck the accelerometer, gyroscope, compass, auto-rotate and vibration motor of a phone right in the browser.Fingerprint and Face ID testCheck the fingerprint sensor, Face ID, Touch ID or Windows Hello through the browser, with an animated step-by-step guide.Battery and charging port testSee the battery level, detect plugging and unplugging to test a loose charging port, and watch how fast the battery drains. Plus how to read battery health on iPhone, Android and laptops.CPU test: performance and overheatingScore single-core and multi-core CPU performance and run a 20-second heavy load to catch overheating and throttling from dried thermal paste, dusty fans or a weak battery.WiFi and network speed testMeasure ping and download speed over several rounds, with average, lowest and highest, to check the WiFi or mobile data of a used phone or laptop.GPS and location testMeasure how long a phone takes to get a location fix and how accurate it is. Your location is never stored or sent anywhere.Manual used-device checklistWhat to check by hand when buying a used device: IMEI, iCloud Activation Lock, Google FRP, battery health, replaced parts, SSD health, laptop hinges.

Buying guides

How to check a used iPhone before you buy itCheck a used iPhone step by step: Activation Lock, IMEI, replaced parts, battery health, screen, Face ID, speakers and cameras. With free tests that run in Safari.How to check a used Android phone before you buy itWhat to check on a used Android phone: Google FRP lock, IMEI, Samsung's *#0*# test menu, battery health, OLED burn-in, touch and cameras.How to check a used laptop before you buy itUsed laptop checklist: screen, keyboard, touchpad, battery wear with powercfg, SSD health, fans and temperatures, hinges, ports and BIOS passwords.How to check a used MacBook before you buy itWhat to check on a used MacBook: Activation Lock, company MDM enrollment, battery cycle count, screen coating wear, keyboard, Touch ID and speakers.How to check the screen of a used phone or laptopHow to spot dead and stuck pixels, OLED burn-in, LCD backlight bleed, replacement screens and dead touch zones on a used phone or laptop, with free tests.How to check the battery of a used phone or laptopRead battery health on iPhone, Samsung, Pixel, Windows laptops (powercfg) and MacBooks, and spot swollen batteries, loose charging ports and fast drain.

Frequently asked questions

What is Soi Máy?

Soi Máy (soimay.com) is a free tool for checking a used phone, tablet or laptop before you buy it, right in the browser with no app to install. It has 17 tests, including dead pixels, touch, speakers, microphone, cameras, battery, keyboard and sensors, plus an IMEI and iCloud checklist and buying guides.

Are online phone tests accurate?

The tests use the device's own hardware (screen, touch, speakers, microphone, cameras, sensors), so they catch real faults. For things a browser can't read, such as battery health, the IMEI or iCloud lock, Soi Máy shows you where to find them in the device's Settings.

How do I check a used phone before buying it?

Open Soi Máy on the phone you are about to buy, tap Test step by step and follow each test: screen, touch, speakers, microphone, cameras, sensors and battery. Finish with the manual checklist to verify the IMEI, iCloud or Google account lock, and battery health in Settings.

Do I need to install an app?

No. Every test runs in the browser (Safari on iPhone, Chrome on Android and laptops), so you can test a seller's device without installing anything on it.

Does Soi Máy record my camera or microphone?

No. The camera, microphone and location are processed only on your device and never sent anywhere. Results are stored only in your browser.

Can a website read battery health?

Browsers are not allowed to read battery health. Soi Máy tests the charging port and how fast the battery drains, and shows you where to find the health percentage in iPhone or Android Settings, or with the powercfg command on Windows.

How can I tell if a used iPhone is iCloud locked?

In Settings, the account name at the top must be empty and Find My iPhone must be off. The safest way is to have the seller erase the iPhone in front of you, then sign in with your own Apple Account.

Why does my iPhone only show 60 Hz on a 120 Hz screen?

Browsers on iPhone limit web pages to 60 frames per second. To check a 120 Hz screen, turn Limit Frame Rate on and off in Settings › Accessibility › Motion and scroll; or turn off the 60 fps option in Safari's Feature Flags, then fully close Safari and reopen it.

How do I save my test results?

On the Results page, tap Save PDF to download a report, or Create report link to send it to someone by message or email.