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Browse Help Topics
The articles people open most, grouped by what you are trying to do.
Getting Started
How Screen Tester works and how to get the best results.
Pixels
Dead, stuck and hot pixels, and what to do.
Panel Problems
Backlight bleed, burn-in and uneven brightness.
Refresh And Motion
Hz readings, ghosting, VRR and input lag.
Returns And Warranty
Using your results with a seller or brand.
Color And Sharpness
Washed-out color, banding, blur and gamma.
Devices And Hardware
Phones, TVs, touch, keyboards, mice and webcams.
Privacy And Safety
Your data, flashing tests and permissions.
Help For Your Device
Choose your screen to get the right tests in the right order, with tips that avoid false alarms.
Recommended Test Order For A Monitor
A new or used desktop monitor, IPS, VA or OLED. About 9 minutes in total.
Monitor Testing Tips
- Test in the first days, inside the return window
- Let the monitor warm up for about 30 minutes before uniformity checks
- Use DisplayPort for high refresh rates
- Keep the report from the Dead Pixel Test
Recommended Test Order For A Laptop
A laptop screen, including gaming and OLED laptops. About 8 minutes in total.
Laptop Testing Tips
- Plug in the charger so the laptop runs at full refresh rate
- Test with the lid at your usual angle
- Set browser zoom to 100% before pixel patterns
- Turn off auto-brightness during tests
Recommended Test Order For A TV
A smart TV, LCD, Mini LED or OLED. About 12 minutes in total.
TV Testing Tips
- Turn off eco and light sensor modes first
- Use the remote to select Full Screen
- Set the input to PC mode when testing from a computer
- Sit where you normally watch
Recommended Test Order For A Phone
A new or second-hand phone, OLED or LCD. About 5 minutes in total.
Phone Testing Tips
- Turn brightness up and auto-brightness off
- Turn the phone sideways for more screen
- On iPhone, the test fills the browser window
- Remove a privacy screen protector first
Recommended Test Order For A Tablet
An iPad, Android tablet or drawing tablet. About 7 minutes in total.
Tablet Testing Tips
- Use landscape for the largest test area
- Check multi-touch with several fingers
- Clean the screen before touch tests
- Compare tint on white and grey
Popular Answers
Quick answers to the questions we get asked most.
Why is my 144 Hz monitor stuck at 60 Hz?
Usually a setting, port or cable is holding it back. Check the monitor's menu, then set the rate in Windows under Settings, System, Display, Advanced display. Use DisplayPort or a high-speed HDMI cable, because older HDMI 1.4 links run out of bandwidth at high resolutions and refresh rates. Update your graphics driver and set the rate in each game too. Read more
How many dead pixels are acceptable on a new monitor?
It depends on the brand, but many follow the ISO pixel fault classes. The common Class II grade allows 2 always-lit, 2 always-dark and 5 sub-pixel faults per million pixels, which is about 4, 4 and 10 on a Full HD screen. Some premium lines promise zero bright pixels, so check your brand's pixel policy and test inside the return window. Read more
What is the difference between backlight bleed and IPS glow?
Bleed stays put, glow moves. Backlight bleed is light leaking from fixed spots at the edges and looks the same from any angle. IPS glow is a silvery haze in the corners that changes or fades as you move your head or sit further back. Glow is a normal trait of IPS panels; strong bleed is a defect. Read more
Does it work on iPhone and iPad?
Yes, with one limit. Safari on iPhone does not allow true full screen for web pages, so the test fills the whole browser window instead. Turn the phone sideways and set brightness manually for the cleanest result. Read more
Can a dead pixel be fixed?
A truly dead pixel cannot be fixed with software. The tiny transistor that drives it has failed. A stuck pixel is different and can sometimes be revived with the Stuck Pixel Fixer. Never press hard on the panel, it can damage more pixels. Read more
How do I use the test result for a return or warranty claim?
Mark the fault, then copy or download the report. Turn on Mark mode, tap each faulty pixel to log its exact x and y position, and attach the report with a photo of the screen to your request. Test as soon as the screen arrives, while the return window is still open. Read more
Why does the pixel checkerboard look grey or blurry?
Your screen is not running at its native resolution, or it is being scaled. A one-pixel checkerboard only looks crisp when every image pixel lands on one panel pixel. Set the recommended resolution and check your scaling settings. Read more
Does Screen Tester upload anything from my device?
No. Every test pattern, reading and report is created inside your browser and stays on your device. Nothing is sent to a server unless you copy or download the report yourself. Read more
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