TV and Monitor Screen Test

What each test shows

Solid colours: dead and stuck pixels

Look closely at each colour, ideally from about arm's length. A dead pixel stays black on every colour. A stuck pixel stays one colour, often red, green or blue, whatever is on screen. A single stuck pixel sometimes frees itself after hours of use. Dead pixels are permanent.

Gradients: banding

A smooth gradient should fade evenly from dark to light. Visible steps or stripes, called banding, can come from the panel, from heavy picture processing, or from the TV's colour settings. Try turning off noise reduction and dynamic contrast in the picture menu, then run the test again.

Black screen: backlight bleed and clouding

Run this in a dark room. Bright patches at the edges are backlight bleed, and blotchy lighter areas across the screen are clouding. A small amount is normal on LCD and LED TVs. OLED screens should look completely black.

Grid and text: sharpness and overscan

The red border should touch all four edges. If it is cut off, your TV is overscanning, enlarging the picture and losing the edges. Look for a setting called Just Scan, Screen Fit, Full Pixel or Overscan off in the picture size menu. This makes everything, including apps, look sharper.

Using it on a TV

Open this page in your TV's web browser, such as Silk on Fire TV, or a browser app on Google TV. Use the remote's arrow keys to choose a test and OK to start, then press OK to move through the colours and Back to exit. For the most accurate result, set the picture mode to Standard or Movie and switch off any eco or ambient light sensor first.

Choosing a new TV? Our viewing distance calculator helps pick the right size, and the codec checker shows which video formats a device supports.