Tool categories
Reads every display property the browser exposes — screen width/height, viewport, device pixel ratio, color depth, color gamut, orientation, and more — and updates live as you resize the window.
Screen Resolution Test is a free, browser-based screen testing tool that runs the full check instantly in your web browser.
Modern browsers expose every relevant display property through the screen object and the window.devicePixelRatio property. This tool reads all of them and formats the results: CSS screen resolution, physical pixel resolution (CSS × DPR), browser viewport dimensions, device pixel ratio, color depth, advertised color gamut, orientation, aspect ratio, and available screen size. Everything runs in JavaScript on your machine — nothing is uploaded.
The big source of confusion: when your phone says "1080 × 2400" physical, the browser reports something smaller like "390 × 844" for screen.width / height. That's because CSS pixels are an abstraction chosen for consistent text size across devices. Multiply by devicePixelRatio (typically 2-3 on phones, 1-2 on desktops) to get the real pixel count. This tool does the multiplication for you.
The color-gamut CSS media query exposes which color gamut the OS and browser advertise. sRGB is the baseline — every display. DCI-P3 is wide-gamut, covering most modern phones, MacBooks, and premium monitors. Rec. 2020 is the UHD standard — rarely matched fully by consumer hardware. If you're doing color-critical work, this tells you whether the browser will render P3 images at full fidelity or remap to sRGB.
Windows DPI scaling (125%, 150%, 175%) reduces the reported CSS resolution — a 4K display at 150% scale reports as 2560 × 1440. macOS HiDPI similarly reports half-size logical resolutions. Browser zoom changes DPR at non-100% settings. Private or strict-privacy modes (Firefox, Brave) sometimes round values for anti-fingerprinting. If your numbers don't match the sticker on the monitor, check OS scale first.
Screen Resolution Test FAQ
Cycle 8 solid colors, fine checkerboard, and scrolling refresher fullscreen to detect OLED burn-in
Detect Full RGB (0-255) vs Limited (16-235) via near-black and near-white patch grids
Fullscreen gray/black/white/RGB at any brightness to spot clouding, IPS glow, and backlight bleed
Detects dropped or skipped frames at your refresh rate with rAF timestamp analysis and a visual reference bar
Lagom-style 1px pixel grid, multi-size text samples, color-fringing blocks, and an RGB sub-pixel ruler to evaluate display sharpness
Detect dead, stuck, or hot pixels on screens
23 tools · 4 Web Stories
01 / 10
Monitor reality check
1000Hz Is Real. Worth $999?
LG's UltraGear 25G590B is the first native 1000Hz 1080p monitor. Check the fine print first.
01 / 10
Phone buying guide
PWM-sensitive? Test the phone, not the promise
Display specs narrow the shortlist, but no OLED is comfortable for everyone.
01 / 10
Screen flicker test
Your screen may be flickering
Many displays dim by switching the backlight on and off hundreds of times a second.
01 / 10
Monitor check
Dark scenes losing detail?
Your monitor may be turning several near-black shades into one flat black.
Source-based buyer analysis of the first native 1000Hz monitor: verified specs, the 1 ms GtG contradiction, the MBR Pro versus G-SYNC/FreeSync trade-off, dated prices against 480Hz OLED and dual-mode alternatives, and five delivery-day browser tests.
