Refresh Rate Test

What this measures, and what it does not

Your browser cannot directly ask your monitor what refresh rate it is set to, that information simply is not exposed to web pages for privacy and security reasons. What this tool does instead is time how often your browser is actually able to paint a new frame, using the same precise timing system every web page relies on, then work backward from that timing pattern to the refresh rate that best explains it. This is a genuine, evidence based estimate rather than a guess, but it is still an estimate drawn from observed behaviour rather than a value read directly from your hardware.

The confidence rating below exists specifically to be honest about that distinction. A high confidence result on a stable system is normally trustworthy enough to treat as your real refresh rate. A low confidence result usually means something else, background load, power saving, or browser throttling, is interfering with a clean reading rather than the test itself being wrong.

Run the test

How to read your results

The headline number

This is the single refresh rate value the detection settled on, rounded to the nearest common rate, since real displays rarely land on a perfectly exact number due to small timing variance even when running correctly. Seeing 59 or 61 rather than a flat 60 is completely normal and still represents a standard 60 hertz display.

Confidence rating

High confidence means the detected frame intervals were tight and consistent enough that the result is very likely accurate. Medium confidence means a clear pattern emerged but with more variance than ideal, often caused by mild background load during the test. Low confidence means the intervals were too scattered to settle on a single clear answer, which usually points to something actively interfering with clean timing rather than a fundamentally unreliable test.

Samples collected and average interval

More samples generally produce a more reliable result, which is why the test runs for a stretch rather than giving an instant answer. Average interval is the mean time between frames in milliseconds, the raw number the detected hertz figure is calculated from.

Interval spread

This shows how much variation existed between individual frame intervals during the test. A small spread means your system held a very steady rhythm, which is exactly what you want to see and is what makes a high confidence rating possible. A large spread means intervals were jumping around meaningfully, which both lowers confidence in the result and is itself worth investigating, since a healthy system at idle should be capable of very steady timing.

Top candidates

This lists the next most likely refresh rates the detection considered, in case your display happens to sit near a value that could be confused with a neighbouring common rate, for instance a system bouncing between something close to 60 and something close to 75 hertz rather than settling clearly on one.

The visual motion check

Numbers are useful, but your own eyes are a genuinely good final check. At a correctly matched refresh rate, the sweeping bar should look like one continuous, fluid motion. Any sense of stepping, doubling, or subtle stutter in the motion, particularly if you compare it side by side with a phone's slow motion camera, is a real signal worth taking seriously even if the number above reports high confidence.

Why your actual refresh rate is worth confirming

A surprising number of monitors capable of 120, 144, or even higher refresh rates end up running at a default 60 hertz simply because a cable was swapped, a driver was reinstalled, or the setting was never changed from how the display arrived out of the box. None of these situations announce themselves, your monitor will not warn you that it has quietly fallen back to a lower rate, so the only way to actually know is to check, either through your operating system's display settings or through a real timing based test like this one that confirms what is genuinely happening rather than what a settings menu claims should be happening.

This matters most directly for anything competitive or fast paced, where the practical difference between 60 and 144 hertz is substantial, but it is worth confirming even for general use, since paying for higher refresh rate hardware that has silently reverted to a lower setting is a surprisingly common and easily overlooked waste.

If your result is lower than expected

Check your operating system's display settings first, since this is by far the most common cause. On Windows, this lives under display settings, advanced display settings, where refresh rate is selectable per monitor. On Mac, it is under displays in system settings. If the correct higher rate is not listed as an option at all, check the cable itself next, since older HDMI or even some DisplayPort cables are not rated to carry a high refresh signal at your resolution and will silently cap the connection without any error message.

If the right rate is listed and selected but this test still detects something lower, browser level throttling or a background power saving mode are the next most likely explanations, both of which are worth ruling out using the same checks covered for frame rate consistency more broadly, closing other demanding tabs and applications, and confirming you are not running on a battery saving profile if you are on a laptop.

Troubleshooting

The result keeps coming back as low confidence

Close other tabs and background applications before testing, particularly anything else doing its own rendering, since shared system load is the most common cause of scattered, inconsistent timing during the test.

The motion check looks slightly juddery even though confidence is high

Try viewing it at a different zoom level in your browser, since browser zoom can occasionally introduce its own subtle rendering inconsistency separate from your actual display's refresh rate. If it still looks off afterward, trust your eyes and treat that as a reason to dig further rather than dismissing it.

My monitor is rated for a high refresh rate but the result is much lower

Check your operating system's display settings first, then the cable, in that order, since both are far more common causes than an actual hardware fault in the monitor itself.

The number is different every time I run the test

Small variation between runs is normal and expected. A meaningfully different result each time, rather than a small wobble around the same number, points toward inconsistent background load between runs rather than the display itself changing.