How the test works
Press Start and leave the tab in front. Every time the browser draws the page it hands the test a timestamp, and the test collects those for the chosen duration: 5 seconds for a quick look, 15 for a steadier number, 60 for a stability check. The first half second is discarded, because the frames right after a click are never regular. From the rest the test takes the median interval between frames and turns it into hertz, so a stray slow frame does not move the number.
The trace in the panel shows every frame as a thin bar. On a healthy setup the bars form a flat row on the lower dashed line, which marks the usual interval. A bar that reaches the upper line is a frame that took twice as long, in other words a refresh the browser missed, and it is drawn in a paler colour. The run ends on its own; the result card then shows the rate, the nearest standard rate, the skipped frames, the longest single frame and how many frames were counted.
Only visible time counts. If you switch to another tab or app the browser stops drawing the page, and the test treats that as a pause rather than as a very long frame.
What the result means
The big number is the rate the browser delivered on this page. It is the refresh rate of the screen when nothing throttles it, which is the usual case on a desktop with the tab in front.
- 60 Hz. The standard for office monitors, TVs, older laptops and most phones. If your screen is advertised as faster, something is holding it back: see the next section.
- 75, 90, 100 Hz. Common on mid-range monitors and phones. A phone that shows 90 here is running its high refresh mode.
- 120, 144, 165, 240 Hz. Gaming monitors and flagship phones. The result should be within a hertz of the marketed rate; 119.9 or 143.9 is normal, since the standard rates are rounded.
- An odd number such as 48 or 72. The browser is drawing at a fraction of the true rate, or the display is in a media mode. Close video players and run again.
- A number with many skipped frames. The panel rate is probably right, but the machine is busy. That is what the fps test is for.
What to do if the rate is lower than advertised
On Windows, open Settings, System, Display, Advanced display and pick the highest refresh rate listed for the monitor; if the highest option is missing, the cable or the port is the limit. Older HDMI cables and ports top out at 60 Hz at 1440p and above, and a DisplayPort cable usually fixes it. On macOS the rate is under Displays; ProMotion laptops set to a fixed 60 Hz stay at 60 in the browser. On a laptop, check the power plan and plug in the charger, because several browsers cap the page at 60 on battery. On a phone, look for Motion smoothness or Screen refresh rate in the display settings and pick the adaptive or high option, then turn off battery saver.
If the settings are right and the number is still low, close other tabs and apps and try another browser. A browser can cap the rate on its own: Safari on iPhone and iPad may hold web pages at 60 even on a 120 Hz screen, and Chrome on some laptops picks the rate of the screen the window started on when two monitors run at different rates.
When to return or claim the warranty
A refresh rate that never reaches the advertised value on a correct cable and the correct setting is a valid reason to return a new monitor within the return window. Take a screenshot of the display settings showing the rate you selected next to this test's result, and note the cable and port you used; support will ask. A panel that reaches its rate but shows skipped frames is not faulty: that is the computer, not the screen. Flicker, lines or a picture that drops out at the high rate but is fine at 60 point to the cable first and the monitor second, and both are covered by a warranty claim if a known-good cable does not solve it.
Frequently asked questions
My monitor is 144 Hz but the test says 60. Which one is right?
Both, in a way. The panel can do 144 Hz, but the operating system or the browser is sending it 60 frames a second, so that is what you see. Open the display settings and check the refresh rate on the monitor itself, and on a laptop check the power plan; several browsers also cap the page at 60 on battery. Run the test again after each change.
Why does the result say approximately?
The browser does not tell a page the refresh rate. The test measures the time between frames it is allowed to draw and takes the median, which is the delivered rate to within a fraction of a hertz on a quiet machine, but it is still an estimate. A heavy download, a video in another tab or a battery saver can lower it while the panel itself is fine.
What is a skipped frame?
A frame interval that is at least one and a half times the usual one, which means the browser missed a refresh. A handful over a minute is normal, especially right after a click. Dozens every second mean the machine cannot keep up, and that is a smoothness problem, not a fault in the screen.
Does the test work on a phone?
Yes, and it is the quickest way to see whether a 90 or 120 Hz phone screen is actually running that fast. Many phones drop to 60 Hz in battery saver mode or when the screen is set to standard rather than adaptive refresh, and some browsers hold web pages at 60 regardless of the panel.
Can the test change my refresh rate?
No. A web page can only observe how often it is drawn. Changing the rate is done in the operating system's display settings, and on some monitors also in the on-screen menu or by using a DisplayPort cable instead of an older HDMI one.