Spot stuck and dead pixels
Against solid blue, a pixel stuck on red, green, or white stands out immediately — far more clearly than it does on a normal page.
Blue screen · One click · No sign-up
Blue screen online,
for pixel tests and cool light.
A clean, saturated blue filling your whole display — for spotting stuck pixels, casting cool light, or putting a plain blue background behind something.
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Take your blue screen with you.
Download a plain blue image for a wallpaper, reference, or offline display check. Choose HD, 4K, mobile, or square in PNG, JPG, or WebP.
One simple tool, useful everywhere
What a blue screen is actually good for
Check backlight uniformity
A mid-tone field like blue is the easiest colour for revealing clouding, banding, and dim patches near the edges of an LCD.
Cast cool ambient light
Dim the screen and angle it at a wall or desk for a cool blue wash — a bias light behind a monitor, or a cold accent for a stream.
Put a plain blue behind something
A saturated, even blue field makes a simple backdrop for a small product shot, a video call, or a photo of a pale object.
How it works
Your blue screen in 2 steps.
- Fill the display. Press Open Blue Screen or click the preview. The blue expands past the browser interface to cover the entire panel.
- Tune and inspect. Drag the brightness down for ambient use, or leave it at 100% and scan the panel corner to corner. Escape exits.
A practical colour guide
Using a blue screen for tests, light, and backgrounds
Why a solid blue field reveals so much
Screens are designed to be looked through rather than at. Text, windows, and images give your eye so much to latch onto that panel faults hide in plain sight. Fill the display with one uninterrupted colour and that camouflage disappears — suddenly you are looking at the panel itself, and dust, smears, clouding, banding, and dim regions all become obvious.
Blue is a particularly useful colour for this because it sits at a mid luminance. Pure white hides dark defects in glare; pure black hides bright ones. A saturated blue is bright enough to expose dead spots and dark enough that a stuck white or red pixel is unmistakable against it.
Running a proper pixel check
Go fullscreen, sit at your normal viewing distance, and sweep your eyes methodically across the panel — corners first, since that is where problems cluster and where attention rarely goes. Then work inward across the middle. Do not press on the screen while you inspect it; pressure produces temporary blotches that look exactly like a fault and can genuinely damage an LCD.
One colour alone is not a diagnosis. Follow this with the other solid colours and compare. A mark visible on every single colour, including black and white, is almost always dust or a mark on the glass — try cleaning it with a dry microfibre cloth first. A dot that is black on blue but invisible on black is a dead pixel. One that shows only on certain colours is a stuck subpixel, and those occasionally recover on their own. What a browser page cannot tell you is whether a fault is covered by warranty, so if something persists, that conversation is with the manufacturer.
Blue as a light source
A display is a large, soft, close light source, and pointing a dim blue one at a wall behind your monitor makes a decent bias light — the faint glow that reduces the contrast between a bright screen and a dark room, which many people find easier on the eyes during evening work. It also flatters a webcam shot by giving the background some separation and colour.
Turn the brightness well down before you do this. Saturated blue at full output in a dark room is genuinely harsh, and blue light in particular tends to feel more intense than its measured brightness suggests. Angle the panel toward a surface rather than at anyone’s face, and if you are on camera, judge the effect in the webcam preview — auto white balance often reacts strongly to a strong colour cast just out of frame.
Plain blue as a background
When a photograph, slide, mood board, or call needs a clean field of colour behind it, a fullscreen blue is the fastest way to get one. Blue is a good backdrop for pale, warm-toned, or metallic subjects because it sits opposite them on the colour wheel and pushes them forward. It is a poor choice behind anything blue or denim, which will simply dissolve into it.
For keying, be realistic about what a monitor can do. Blue screen work is legitimate — the industry used it before green, and it remains the better option when a subject wears green. But the shade here is #2563EB rather than a broadcast blue, and a glossy panel introduces reflections and uneven brightness that a keyer will fight. For casual keying, the green screen is more forgiving.
Taking the blue with you
The download control saves a plain blue image at HD, 4K, mobile, or square dimensions in PNG, JPG, or WebP, generated in your browser with nothing uploaded. That is the version you want for a wallpaper, a background layer in a design file, an offline display check, or a device you cannot keep a browser open on.
The Copy button puts #2563EB on your clipboard for use in a design tool. And if blue is not the colour you needed, the purple, yellow, orange, and pink screens work identically, as does the green screen.
Helpful answers
Blue screen FAQ
Is this the Windows blue screen of death?
No. This is a plain blue colour tool you open deliberately — nothing has crashed. The Windows stop screen shows an error code and a sad face on a different, darker blue. If you landed here looking for that, your computer is fine.
How do I test for dead pixels with a blue screen?
Go fullscreen, then scan slowly from corner to corner from a normal viewing distance. A dot that stays bright, dark, or oddly tinted is a candidate. Repeat on red, green, white, and black — a dot that persists across every colour is usually dust or a dead pixel, while one that changes is a stuck subpixel.
What blue does this page use?
#2563EB, RGB 37, 99, 235 — a strong mid-blue chosen to be vivid without the eye strain of a fully saturated primary. Use the Copy button to grab the hex value for a design tool.
Can I use a blue screen for chroma key?
Blue screen keying is a real technique, and it is the right choice when your subject wears green or has green props. But a display is not a keying backdrop: this shade is not the broadcast blue standard, and a monitor is too small and too uneven in reflectivity for a clean key. Use the green screen for casual keying, or a proper lit backdrop for real work.
Why does the blue look different on my phone than my monitor?
Because the panels differ. OLED phones render saturated blues far more intensely than most LCDs, and colour profiles, HDR handling, brightness, and night-shift modes all shift the result. The pixel value is identical; the light reaching your eye is not.
Does it work on iPhone and Android?
Yes, in any current mobile browser. Tap the preview for the largest view your device allows. A phone showing solid blue also makes a handy little light source for close-up work.