Temporal Sync Diagnostic • 0 Hz
When you look at your computer monitor, it might look like you are watching a smooth, moving video. But really, your screen is flashing many different pictures very, very fast. The speed at which your monitor does this is called the Refresh Rate, and it is measured in Hertz (Hz). At Hardware Tester, our Refresh Rate Lab helps you see exactly how fast your screen is blinking.
Whether you are an office worker who wants a comfortable screen for reading or a pro gamer who needs every millisecond of speed, our tool is the most accurate way to verify your hardware. We use clinical monitoring to check the "pulse" of your display with sub-millisecond precision.
Hertz (Hz) is a way to count how many times something happens in one second. If your monitor is 60Hz, it means it draws a new picture 60 times every single second. If it is 144Hz or 240Hz, it is much faster and smoother! High refresh rates make moving things (like your mouse cursor or a character in a game) look crystal clear instead of blurry. Our tool shows you your "Real-Time Refresh Rate" so you know you are getting what you paid for.
It's not just about how many frames you get, but how consistent they are. Frame Time is the amount of time (in milliseconds) between each new picture. If one frame takes 16ms and the next takes 20ms, that tiny difference is Jitter. Too much jitter makes the screen look like it is stuttering or "hiccuping." Our Hardware Tester engine tracks this jitter to tell you if your monitor is working perfectly smooth or if it has a problem.
Update: Feb 2026 (v3.8.22)
Added support for 500Hz+ ultra-high speed monitors. Improved the "Sync Locking" detection to better identify V-Sync issues. New "Stability" rating (Clinical, Standard, or Unstable) based on frame-time variance.
Update: Nov 2025 (v3.2.0)
Introduced the "Temporal Jitter" graph. Now you can see a live visual history of every frame your monitor draws. Fixed a bug where some dual-monitor setups were showing the wrong speed.
Verify Windows Settings
Sometimes people buy a 144Hz monitor but forget to change the settings in Windows. If our tool says "60 Hz," it means you aren't using the full power of your screen!
Detect Frame Skipping
Some monitors try to "fake" a high speed but actually skip pictures. Our Refresh Rate Lab helps you find out if your monitor is being honest.
Smooth Video Calibration
If your movies or games look a bit jittery, check your Stability score. A stable monitor makes everything look more like a high-budget film.
Ready to see how fast your screen is? Just follow these steps:
Expert Tip: To get the most accurate result, make sure you don't have any other browser windows open. Even a small moving ad on another page can cause jitter!
Display Sync Standard V-2026 • Accuracy Tolerance +/- 0.01Hz
Why does my 144Hz monitor show 60Hz?
This is a common issue! Right-click your desktop, go to Display Settings, and look for "Advanced Display." Make sure the "Refresh Rate" dropdown is set to 144Hz. Our tool will then update instantly!
What is "Overclocking" a monitor?
Some people push their monitors to go faster than they were built for. Our tool is perfect for checking if an overclock is stable or if it's causing too much jitter.
Why is the number slightly different (like 59.98)?
Monitor timing is based on tiny electrical pulses that aren't always exactly perfect. If you are within 0.1Hz of your target, your monitor is working exactly as it should!