Resolution Checker Online
What resolution is your screen really running? This resolution checker shows your live native resolution, viewport, pixel ratio, and color depth — plus a pixel-grid test to confirm you're at native resolution.
Your display info
Reading display info…
Native is your screen's hardware resolution. Viewport is the browser window size in CSS pixels. DPR above 1 means a HiDPI/Retina display with scaling applied.
Pixel grid
4px checkerboard
Click to open the pixel-grid test
Fullscreen · at native resolution the 1px grid renders crisp
Native Resolution vs. Scaled: Why It Matters
Running below your screen's native resolution forces the display to scale the image, which blurs text and can hide dead pixels. Always test and use the panel's native resolution.
Native resolution
One image pixel maps to one physical pixel. Text is crisp, the 1px checkerboard is sharp, and dead-pixel tests are accurate.
Scaled (non-native)
The image is stretched or shrunk to fit. Text softens, the pixel grid looks muddy or moiréd, and tiny defects can be hidden.
Set Your Native Resolution
Match the OS output resolution to the panel's native resolution shown above, and turn off any display scaling that shrinks the desktop below native. This keeps text sharp and ensures every physical pixel is addressable.
Resolution Checker FAQ
What's the difference between native resolution and viewport?
Native (device) resolution is your screen's hardware pixel count. Viewport is the browser window size in CSS pixels. On a HiDPI/Retina display the viewport is smaller than native because of scaling — that's where the device pixel ratio comes in.
What does device pixel ratio (DPR) mean?
DPR is how many physical pixels back one CSS pixel. DPR 1 = standard; DPR 2 (Retina) = 4 physical pixels per CSS pixel; DPR 1.5/1.25 = Windows scaling. Higher DPR means sharper text but more GPU load.
Why does the 1px checkerboard look fuzzy?
If it looks muddy, streaky, or shows moiré, you're likely not at native resolution, or the browser/display is applying scaling. Set the OS to the panel's native resolution and 100% scaling (or the panel's recommended scale) and re-test.
Why is my "4K" monitor showing 1920×1080?
The OS is outputting 1080p and the monitor is upscaling it. Set the display resolution to 3840×2160 in your system display settings, and use a cable (DisplayPort 1.4 / HDMI 2.1) that supports 4K.