STATE-OF-THE-ART REFRESH RATE TEST

Screen Refresh Rate Test

Measure true hardware display Hz, microsecond inter-frame jitter, mobile ProMotion LTPO dynamic refresh scaling, and esports 540Hz+ frame pacing instantly in your browser.

WARNING: PHOTOSENSITIVE SEIZURE & FLICKER HAZARD

A small percentage of individuals may experience epileptic seizures or photosensitive reactions when exposed to flashing lights, high-contrast strobing, or rapidly moving visual patterns. In compliance with WCAG 2.1 Success Criterion 2.3.1 (Three Flashes or Below Threshold), Monitor Test Hub limits default strobing animations. However, dynamic visual tests inherently involve rapid refresh intervals.

Discontinue use immediately and consult a physician if you experience dizziness, altered vision, twitching, loss of awareness, or disorientation while running tests.

W3C HIGH-RESOLUTION TIME API & ISO 9241-307

Screen Refresh Rate & Frame Pacing Inspector

DETECTING REFRESH RATE...

Measured Real Hz

0.00 Hz

Nominal: --

Average Frame Time

0.00 ms

Target: 16.67ms

Inter-Frame Jitter (σ)

0.00 ms

P99: 0.00ms

Mobile ProMotion / LTPO

DETECTING...

Range: --

Side-by-Side Multi-Rate Motion Sweep (1x, 1/2x, 1/4x, 1/8x)

Target Hz Filter:AUTO (DETECTING)

🔬 ISO 9241-307 & W3C Frame Pacing Telemetry Standards

1. Microsecond Precision

Measures exact frame presentation intervals using sub-millisecond browser compositor timestamps rather than standard rounded integer counters.

2. Mobile LTPO / ProMotion

Evaluates dynamic variable refresh rate scaling, detecting energy-saving idle drops down to 10Hz and touch-boosted 120Hz gaming performance.

3. Multi-Rate Pursuit

Displays side-by-side 1x, 1/2x, 1/4x, and 1/8x motion sweep reticles for evaluating sample-and-hold display motion blur and tracking clarity.

HELPFUL TECHNICAL CONTENT & FAQS

Frequently Asked Questions

Everything you need to know about this diagnostic instrument, calibration procedures, and display technical standards.

01.How does the Screen Refresh Rate Test measure real hardware Hz?

Our engine uses W3C High-Resolution Time (performance.now()) microsecond hardware timestamps combined with requestAnimationFrame compositor callbacks to measure your display's true physical refresh rate and inter-frame pacing deltas.

02.How do I test dynamic ProMotion or LTPO refresh rates on iPhone, iPad, or Android?

On dynamic mobile displays (such as Apple ProMotion or Samsung LTPO), the screen drops to 10Hz–30Hz when idle to save battery. Swiping or touching the screen triggers maximum 120Hz boost mode, which our real-time LTPO inspector automatically measures.

03.Why does my 144Hz, 240Hz, 360Hz, or 540Hz monitor only show 60Hz?

If your high-refresh gaming monitor displays 60Hz, check your operating system display settings (Windows Display Settings -> Advanced Display Settings -> Choose Refresh Rate). Ensure you are using a DisplayPort 1.4/2.1 or HDMI 2.1 cable capable of high bandwidth.

04.What is inter-frame jitter and micro-stutter?

Inter-frame jitter (measured in milliseconds σ) quantifies variance in frame delivery timing. High jitter causes visual micro-stutter even when average FPS appears high.

05.Can I test high refresh rate screens in any web browser?

Yes, modern Chromium (Chrome, Edge, Brave), Firefox, and Safari support hardware-accelerated requestAnimationFrame callbacks up to 540Hz+. Ensure browser hardware acceleration is enabled in settings.

06.How does VSync, G-Sync, and FreeSync affect refresh rate test results?

Variable Refresh Rate (VRR) technologies like NVIDIA G-Sync and AMD FreeSync dynamically synchronize your monitor's refresh rate to the GPU frame dispatch rate. Disabling VSync during testing allows measuring uncapped browser compositor performance.

07.What is display motion blur and Pursuit Camera reticle testing?

Sample-and-hold display tech (LCD/OLED) causes motion blur as human eyes track moving objects. Our pursuit motion sweep reticles display side-by-side moving targets at 1x, 1/2x, and 1/4x speeds to evaluate panel response time and overdrive ghosting.

08.Why does my frame rate drop when switching web browser tabs?

Web browsers automatically throttle requestAnimationFrame callbacks for background or unfocused tabs to save CPU/GPU power and battery. Keep the test window focused for accurate hardware measurements.

09.Does a higher refresh rate reduce input latency in competitive gaming?

Yes. Higher refresh rates reduce visual frame delay ($1000 ext{ms} / 240 ext{Hz} = 4.16 ext{ms}$ vs $1000 ext{ms} / 60 ext{Hz} = 16.67 ext{ms}$). This gives competitive players a ~12.5ms click-to-photon advantage.

10.How do I enable 120Hz or 144Hz output on macOS or Windows laptops?

On macOS: System Settings -> Displays -> Refresh Rate -> Select 120Hz or ProMotion. On Windows: Settings -> System -> Display -> Advanced Display -> Select Refresh Rate.