Blue Screen

This blue screen page has two jobs. As a color screen it fills your display with solid blue in one click: pure blue checks the blue subpixels of a monitor or TV, chroma key blue gives a keying backdrop for small products and screen replacement in video, and sky blue and navy make a calm room light. If you are here because Windows crashed to a blue screen with a stop code, the section on fixing a blue screen of death below lists the steps that solve most of them. The page runs in Chrome, Edge, Safari and Firefox on computers, tablets and phones.

How to use the blue screen

1. Pick a shade: Pure blue for testing, Chroma key for keying, Sky blue or Navy for light.
2. Adjust brightness. For keying, match it to your camera exposure so the blue is bright but not clipped.
3. Click the preview, tap it, or press F to fill the display. The pointer hides after two seconds.
4. Use the arrow keys or swipe to change shade and brightness in full screen. Esc or a double tap exits.
5. Save the blue as a PNG at your screen's resolution or 4K with Save image if you need a blue screen background file.

The blue shades

Blue screen or green screen for keying?

Both work because few objects and few skin tones contain them. The choice depends on the shot:

• Green keys cleanly with less light. Camera sensors have twice as many green photosites as red or blue, so the green channel has the least noise. It is the default for most video.
• Blue spills less light onto the subject, keeps blond and light hair cleaner, and is the safe choice when someone wears green or the scene is at night. It needs more light because cameras record blue with more noise.

A screen showing chroma key blue works as a backdrop for small objects, hands and products, and for filming a phone or monitor whose picture you will replace in editing. Turn off lights that reflect in the screen, keep the subject at least an arm's length in front of it to cut spill, and focus on the subject so the screen's pixel grid blurs and does not cause moiré.

Check the blue subpixels

Your eyes are least sensitive to blue, so faults are harder to see than on green or white. On a pure blue screen, look closely for:

• Dark dots: blue subpixels that do not light.
• Red, green or white dots: stuck subpixels that stay on.

Confirm anything you find with the dead pixel test, which shows every test color in turn, and use a black screen to make stuck pixels stand out.

Fix a Windows blue screen of death

A blue screen of death, or stop error, means Windows hit a problem it could not recover from and restarted to protect your files. Windows 11 version 24H2 shows the same error on a black screen. Write down the stop code, such as CRITICAL_PROCESS_DIED or MEMORY_MANAGEMENT, and any file name shown, because a name such as nvlddmkm.sys points straight at the NVIDIA graphics driver. Then work through these steps, most likely fix first:

1. Undo the last change. If the crashes began after new hardware, a new driver or an update, remove the hardware, roll back the driver in Device Manager, or uninstall the update in Settings > Windows Update > Update history > Uninstall updates.
2. Update drivers. Get the graphics driver from NVIDIA, AMD or Intel, and check Settings > Windows Update > Advanced options > Optional updates for others. Right click Start, open Device Manager and look for devices with a warning symbol.
3. Repair system files. Right click Start, open Terminal (Admin), run sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth, and restart.
4. Test the memory. Run Windows Memory Diagnostic from the Start menu, or the ram test for a quick check. Memory errors cause random stop codes.
5. Check temperatures. Crashes during games or heavy work often come from heat. Compare your cpu temperature and graphics card temperature with normal ranges, and clean the fans.
6. Free some space. Microsoft advises keeping about 10 to 15% of the system drive free.
7. Start in Safe Mode if Windows crashes before you can sign in. When Windows fails to start several times in a row, it opens the recovery screen by itself. Choose Troubleshoot > Advanced options > Startup Settings > Restart, then press 4. From Safe Mode you can remove a bad driver or use System Restore.

Windows saves a small crash file in C:\Windows\Minidump for each stop error. Microsoft's WinDbg, free from the Microsoft Store, reads it and names the driver involved. Microsoft's own steps are on its stop error troubleshooting page.

Looking for less blue light, not more?

If you want a screen that is easy on the eyes at night, blue is the wrong color. A warm orange screen light or Night light in Windows display settings cuts the blue part of the light, and Night Shift does the same on Apple devices.

What a blue screen in a browser cannot do

The page shows a color. It does not reproduce or fake Windows errors, and it cannot read your crash files. A screen used as a keying backdrop makes its own light, so it lights the back of your subject and is too small to stand behind a person. For any other color, open the color screen and type a hex code.

Blue screen questions