Test My Screen
Third-partyFull-screen solid colours and gradients to spot dead pixels, tint and uneven brightness. Works with touch.
Limit: Mobile browsers may not hide their address bar, so a thin strip of the page can remain visible.
Open websiteMobile Testing Center
Display, camera and audio
Dead pixels, touch, every camera lens, microphone and speakers.
Display tests
- 1Set brightness to maximum. Open a solid colour test (white, black, red, green, blue). Look for dots that stay a different colour (stuck) or stay black (dead).
- 2On black, look for light leaking at the edges or uneven bright patches. On white, look for a yellow or pink tint, white spots and darker corners.
- 3Look for green, pink or purple lines. They usually mean a damaged display or a failing panel.
- 4OLED burn-in: show a plain grey screen and look for faint shapes, such as a keyboard or navigation bar.
- 5Touch: drag across the whole screen and into every corner. Use two and three fingers to test multi-touch (pinch to zoom in Photos or Maps).
- 6Refresh rate: on phones with a high refresh rate option, switch it on in Display settings and check that scrolling looks smoother.
Tip. A test page in a phone browser may leave the address bar visible, so a thin strip of the page can remain. Rotate the phone to landscape and use the full-screen button on the test page.
Dead Pixel Test
Third-partyColour tests for computers, and a full-screen video test made for phones and tablets.
Limit: Shows ads and sets cookies. Its flat colour tests are not meant for phone browsers.
Open websiteEIZO Monitor Test
Third-partyA thorough monitor test from a display maker. Good on a tablet or computer, less so on a small phone.
Open websiteOLED or LCD, and replaced screens
A replaced screen is not always a defect, but it should be priced in. Signs: colours or brightness that look different from the same model, a visible gap or glue at the edge, a missing True Tone switch on an iPhone that should have it, or a Parts and Service History entry that is not genuine.
Aftermarket OLED screens often use more battery and look slightly bluer or dimmer. Compare with another phone of the same model if you can.
Cameras
- 1Take a photo with the front camera and each rear lens: main, ultrawide, telephoto and macro, where the phone has them. Zoom in on the pictures.
- 2Tap to focus on something near and far. Focus must lock in about a second without hunting.
- 3Look for dust or spots that show in the same place in every photo. This is dust inside the lens.
- 4Blurry corners, a ring or haze means a scratched or misaligned lens.
- 5Record a 10 second video while walking. Check that stabilisation works and that the sound is recorded.
- 6Turn the flash on in the camera app and in the torch.
- 7Hold the phone gently with the camera open. A rattle or a buzzing camera can mean a failed stabilisation unit.
Warning. Any camera that shows a black screen, a green tint or will not open is a hardware fault.
Audio
- 1Play music on the loudspeaker at full volume. It must not crackle or sound muffled.
- 2Make a call and listen on the earpiece, then on speakerphone.
- 3Record a voice note and play it back to test the microphone. On phones with several microphones, record in normal and video mode.
- 4Plug in headphones or a USB-C headset, or connect Bluetooth earbuds, and play audio.
- 5Test the volume buttons and the mute switch.
Common questions
A phone browser test page is not full-screen. Is it useless?
No. It is still good for tint, lines and large dead pixels. Rotate the phone and use the full-screen button on the page.
How do I tell dust in the lens from a dirty lens?
Wipe the lens with a soft cloth first. Spots that stay in the same place in every photo are inside the lens.
Ready to test a phone?
Our checklist walks you through every test, scores it, and gives you a report to print or save. It stays on your phone.
Open the checklist