Screen Refresh Rate Test: Check Your Display's Hz

What this refresh rate test checks

Refresh rate is how many times per second your screen redraws its image, measured in Hertz. A 144Hz display redraws up to 144 times a second. This test measures that number as it's actually being delivered to your screen right now, through your operating system, cable, and browser combined, rather than just reading a spec off a box.

How to use the refresh rate test

• Let the test run for a few seconds after the page loads, it needs a moment to stabilize.
• Close other tabs and resource-heavy programs so nothing competes for system resources during the test.
• Compare the result against your display's advertised refresh rate.
• Refresh the page or click to test again if you want to double-check the reading.

Testing on your phone

Run the test the same way in your phone's browser. One thing worth checking first: many phones ship with their display mode set to "Standard" (60Hz) rather than "Adaptive" or the phone's true maximum, even on hardware that supports 90Hz or 120Hz. Check your phone's display settings for a refresh rate or motion smoothness option before assuming the hardware can't do better.

Testing on a laptop

Laptops add one extra variable worth knowing about: battery-saving power modes frequently cap the screen at 60Hz to conserve power, even on panels rated for 120Hz or higher, and this often happens automatically whenever you unplug from power. If your laptop's refresh rate reads lower than expected, check that you're on a high-performance or balanced power plan, especially if you're running on battery.

What your results mean

Hz vs FPS, what's the difference

These get used interchangeably, but they're not quite the same thing. Refresh rate (Hz) is your display's raw hardware capability, how many times it's physically able to redraw the image per second. Frame rate (FPS) is how many actual new frames your GPU is producing per second, which depends on whatever content is being shown. A 144Hz monitor can display up to 144 unique frames a second, but if you're watching a video encoded at 30fps, you're only seeing 30 distinct frames, no matter how capable the screen is. Because browsers sync their rendering to your display through a mechanism called V-Sync, this test is effectively measuring your display's actual active refresh rate as delivered through your system, which is exactly what you want to know.

Does it matter if it's LCD, LED, or OLED?

Not for this test. Refresh rate as a concept works the same way regardless of the underlying panel technology, LCD, LED-backlit LCD, or OLED. If you searched for an "LCD refresh rate test" or "LED refresh rate test" specifically, you're looking for the same measurement, panel technology affects things like contrast, black levels, and response time, but not how refresh rate itself is tested or reported.

Common refresh rates and what they're actually good for

Why your display might be running below its rated refresh rate

Cable and port limits

Not every cable can carry every refresh rate at every resolution. As a general guide, HDMI 2.0 tops out around 144Hz at 1440p, DisplayPort 1.2 can generally handle up to around 165Hz at 1440p, and pushing high refresh rates at 4K typically needs HDMI 2.1 or DisplayPort 1.4. An older or lower-spec cable, or a USB-C dock and adapter in the signal path, can silently cap your refresh rate without any obvious warning. If your result reads lower than expected, checking your exact cable's rated bandwidth against your target resolution and Hz is a good early step.

Mirrored or duplicated displays

If you're running two displays in mirror or duplicate mode, your system will force both screens down to whichever refresh rate they can both support, which is very often the lower one. Switching to extended display mode instead lets each screen run at its own true maximum.

Adaptive and variable refresh rate

Some displays don't run at one fixed number by design. Apple's ProMotion, for example, adapts between low rates and 120Hz depending on what's on screen, so a momentary lower reading on a mostly static page is expected behavior, not a fault. Variable refresh rate technologies like G-Sync and FreeSync work differently again, letting the display match its refresh rate to whatever frame rate your GPU is actually outputting in real time, which reduces tearing and stutter especially when frame rates fluctuate during gaming.

A more complete way to verify your true refresh rate

Worth being upfront about this: this test measures what's actually reaching your display through your operating system, cable, and browser combined, which is a genuinely useful, real-world reading. But it's one signal in a chain, not the final word on its own. Your OS display settings show your intended setting, not proof it's actually happening. This browser test shows what's actually being delivered and rendered. And if you want an independent confirmation beyond both of those, your monitor's own on-screen display menu (usually accessed through physical buttons on the monitor itself) reads the incoming video signal directly at the display, which is closer to ground truth than anything happening further up the chain. If your OS says one number and this test agrees, but your monitor's OSD reports something different, that points specifically to a cable, port, or signal negotiation issue between your computer and the display itself.

Troubleshooting common issues

• Result shows 60Hz on a monitor rated for 120Hz or higher. Check your OS display settings first to confirm the higher refresh rate is actually selected, since systems commonly default to 60Hz. Then check your cable and port against the bandwidth guidance above, and confirm you're not in mirrored display mode.
• Result is inconsistent or jumps around between attempts. Close other tabs and background applications, since competing system load can cause temporary frame drops during measurement. On adaptive displays like ProMotion panels, some variation on static content is expected rather than a problem.
• Laptop refresh rate drops when unplugged. This is typically battery-saving power management, not a hardware fault. Check your power plan settings and switch to high performance or balanced mode to test the panel's true capability.
• Phone doesn't show your expected refresh rate. Check your phone's display settings for a refresh rate or motion smoothness toggle, many devices default to a lower fixed rate out of the box even on capable hardware.
• Browser result and monitor's OSD disagree. Trust the monitor's OSD as the closer-to-hardware reading in this case, and work back through your cable, port, and OS settings to find where the mismatch is happening.

While you're checking your display, it's also worth taking a moment to check for dead or stuck pixels.

FAQ