Real Hz Measurement
Uses requestAnimationFrame timestamps to calculate your display's actual refresh rate over several seconds — accurate to within about ±1 Hz on a stable browser.
Refresh Rate Tester
Measure Your Real Screen Hz
Find out how many frames per second your display actually delivers. Measure live Hz with requestAnimationFrame, compare against the claimed rate, and run motion blur and flicker tests — right in your browser.
Ready to measure
Measured Refresh Rate
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Hz
Estimated display: —
Frame Time
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Frames
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Stability
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Jitter
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Frame Time Graph
Idle
Features
What This Refresh Rate Tester Does
Everything you need to verify your display's real-world performance.
Estimated vs Claimed
Compares your measured rate against a screen-derived estimate from your device and resolution, highlighting any gap between advertised and real Hz.
Frame Time Graph
Live histogram of each frame's interval with stability and jitter statistics, so you can spot stutters, drops, and inconsistent frame pacing at a glance.
Motion Blur Test
A full-screen moving object reveals ghosting and smearing. On high-refresh panels it stays sharp; on slow panels you'll see trailing behind the motion.
Flicker / PWM Test
Full-screen flicker pattern to test for PWM dimming artifacts and motion persistence. Great for checking eye comfort on OLED and LCD panels.
Works Everywhere
Runs in any modern browser on phones, tablets, laptops, and desktops. No app download, no permissions, no data ever leaves your device.
How It Works
Test Your Refresh Rate in 4 Steps
No app, no sign-up — just an accurate reading in seconds.
Prepare
Close other tabs, disable battery saver, and set your display to its highest refresh rate in system settings.
Start Measurement
Tap "Start Measurement". The tester samples requestAnimationFrame for 4 seconds and averages the frame intervals.
Read Results
Your measured Hz appears instantly, with frame time, stability, and jitter stats plus a verdict against the claimed rate.
Run Visual Tests
Launch the motion blur and flicker tests to evaluate response time, ghosting, and PWM behavior full-screen.
FAQ
Refresh Rate Tester — Common Questions
Everything you need to know about measuring your screen's Hz.
The tester uses the browser's requestAnimationFrame API to record the timestamp of every rendered frame. By calculating the average interval between frames over a few seconds, it derives your display's actual refresh rate in Hertz. The measurement is accurate to within about ±1 Hz on a stable browser.
Several factors can lower the measured rate: browser throttling, power-saving modes, the device not actually running at its advertised rate, background apps consuming GPU resources, or the browser being limited to 60Hz even on a higher-refresh display. On phones, the OS often dynamically scales refresh rate based on content, which can also affect results.
Open this page in your phone's browser, ensure the display is set to its highest refresh rate in system settings, disable battery saver, and tap "Start Measurement". Keep the screen active and avoid touching it during measurement. If the result shows 60Hz on a 120Hz phone, the browser may be capped — try a different browser or check that the system setting is enabled.
The UFO test animates a moving object across the screen at a speed matched to your measured refresh rate. On higher-refresh displays the object appears sharper and smoother. On lower-refresh or blurry panels you'll see ghosting or smearing trailing behind the object, which indicates pixel response time and motion clarity issues.