About Refresh Rate Tester

For more than a decade, PC gamers, esports competitors, display reviewers, and software engineers have relied on aging web tools created in the early 2010s to test monitor refresh rates. While those early pioneers paved the way, the web landscape has evolved:

• Modern Monitors Span Massive Refresh Ranges: From 60Hz office displays to 120Hz ProMotion screens, 144Hz and 240Hz competitive panels, up to 360Hz and 540Hz esports monitors, display technology required a modernized testing suite capable of sub-millisecond precision.
• Legacy Portals Suffer From Main Thread Bottlenecks: Older testing tools are burdened with heavy legacy libraries and unoptimized background polling. These bloated scripts compete for CPU cycles and delay the event loop, causing artificial frame stutters that make a healthy display appear jittery.
• Design Matters: We believe essential developer and hardware utilities should embody the clean, distraction-free aesthetic pioneered by modern web engineering leaders like Vercel and Apple.

When you visit Refresh Rate Tester, our JavaScript engine connects directly to your GPU’s compositor pipeline via the browser’s native window.requestAnimationFrame() API:

1. High-Precision Timestamping: Each frame callback provides a monotonic timestamp with microsecond accuracy via performance.now().
2. Harmonic Delta Averaging: The engine records consecutive frame intervals over a sliding rolling window (up to 180 samples), discarding anomalous compositor startup pauses to isolate true hardware frequency.
3. Real-Time Oscilloscope: Rather than just showing a single static number, our engine computes standard deviation (jitter) in milliseconds, plotting real-time VSYNC cadence so you can visually verify frame pacing integrity.