How I Built a Free Browser-Based Monitor Testing Tool with Astro

A few months ago, I bought a new monitor. Like any careful buyer, I wanted to check it for dead pixels, backlight bleed, and color accuracy before the return window closed. I searched online for a tool. What I found was frustrating — every tool only did one thing. One site tested dead pixels. Another was just a black screen for backlight bleed. Color accuracy tests were on yet another domain. None of them worked well on mobile. Most had intrusive ads that defeated the purpose of a "full screen" test. So I built DisplayMaster — a free, all-in-one browser-based monitor testing tool. No downloads. No sign-up. Just open and test. What It Does DisplayMaster covers the three most important monitor quality checks: 🔴 Dead Pixel Detection Cycles through solid color screens — red, green, blue, white, and black — to help you spot stuck or dead pixels instantly. Dead pixels appear as dots that don't change color when the background does. 💡 Backlight Bleed Test Displays a full black screen. In a da