How to Test a Used Phone Before Buying

Start with the basics

Look over the body in good light. Check for a swollen back, separated screen, loose buttons, cracked camera glass or signs of moisture around openings. Plug in a known-good cable if the seller agrees and see whether charging begins. A phone that becomes unusually hot, smells unusual or has a visibly lifting screen should be avoided until assessed by a qualified repairer.

Ask the seller to remove their account and reset the device through its own settings before you buy it. Do not rely on a browser test to confirm ownership status, network lock status, storage condition or the history of repairs.

Screen and touch

Use the dead pixel test to fill the screen with solid colours. Look closely for small points that remain black, bright or a different colour. A single mark may or may not matter to you, but it is useful information before agreeing a price.

Next open the touch screen test. Draw across the whole display slowly, including corners and edges. Missing sections, unexpected lines or touches that stop midway deserve a second check after cleaning and restarting the phone. Small scratches can be cosmetic; a touch area that will not respond is more serious.

Camera, microphone and sound

Allow camera access only if the seller is present and agrees. The webcam test can show a live image from an available camera. Switch between front and rear cameras through the phone’s normal camera app too, as browser access can differ by device.

Speak normally into the mic test, then make a sample with the voice recorder and play it back. Use the sound test for the speakers. Listen for a very quiet output, harsh distortion or a channel that is noticeably absent. Keep the volume modest, especially in public places.

Movement, vibration and battery

The vibration test can show whether browser-controlled vibration is available and responsive, although some phones and browsers do not support it. The battery test may show charge information in some browsers, but it cannot measure a battery’s true capacity or predict its remaining life.

Check whether the percentage changes while charging and whether the phone remains stable during the few minutes you use it. Battery health claims need confirmation in the phone’s own settings where available, and even those are estimates rather than guarantees.

Finish safely

1. Make a normal call or ask the seller to demonstrate one. This checks more than a browser can, including earpiece and mobile connection.
2. Check Wi-Fi, buttons and ports. Use the phone’s own settings and a cable you trust.
3. Confirm the reset. The device should begin setup without asking for the previous owner’s account.
4. Keep your personal details private. Do not enter passwords, payment details or recovery codes into a phone you do not own.

Frequently asked questions