All display processing is performed only within the browser, and screen information is not sent or saved to the server. This tool does not automatically determine failures, but provides a display for users to visually check the screen.

Test settings

Before starting full screen display, you can choose the display color and automatic switching interval.

Display colors and patterns Automatic switching interval

custom color

Suppress sleep during testing

Full screen: Ready Sleep suppression: Ready Display scale: 100% display recommended

Display colors and test patterns

Press the button to switch between preview and full screen test display.

test preview

Click/tap on the preview to move to next, right-click to move to previous.

black Look for bright dots that are always on. ← Previous / → · Space Next / A Auto-switch / Esc Exit

Precautions when checking

Set your browser's display magnification to 100%, clean the screen, and then look at it from a distance.
Displaying black, white, red, green, and blue in order makes it easier to distinguish between points that are not lit and points that are always lit.
1px patterns may not be displayed accurately depending on the browser, OS, or display magnification process.
With OLED, avoid displaying the same bright screen for long periods of time, and use automatic switching only for as long as necessary.
If you feel unwell due to strong light or color changes, please end the test immediately.

About this tool

When purchasing a display or checking for defects, you can display single colors, grays, stripes, and gradations, and visually check for missing dots, constant lighting, color unevenness, and gradation discomfort.

Features

Full-screen display of black, white, RGB, CMY, gray, and any color
1px checkered pattern, vertical and horizontal stripes, gradation, RGB gradation, four corner/center guides, automatic switching, sleep suppression

How to use

Select a display color or test pattern, then start the full-screen test.
Check the entire screen while switching the display with arrow keys, Space, clicks, or taps.
Exit the full screen with Esc and check with a different color or pattern if you wish.

Limitations

This is not a feature that automatically determines physical pixel failures; users must visually inspect the display result.
The appearance of the 1px pattern is affected by the browser magnification, OS display magnification, and display scaling.

Privacy: Generating and switching colors and patterns is done within the browser, and screen information and confirmation results are not sent or saved to the Develop Tools server.