Refresh Rate Test

Almost always because the computer is sending 60 Hz. On Windows 11, open Settings, then System, Display, and Advanced display, and pick the highest rate under Choose a refresh rate (on Windows 10 it is Advanced display settings). On a Mac, open System Settings, then Displays, select the screen, and choose the rate in the Refresh Rate menu. If the higher rate is not offered, the connection is the usual suspect: use the cable that came with the monitor, prefer DisplayPort, avoid adapters and docks, and on a desktop plug into the graphics card rather than the motherboard. Check that the browser has hardware acceleration switched on and that no battery saver is active, then measure again.

Variable refresh rate (G-Sync, FreeSync, Adaptive-Sync, and ProMotion) lets the screen refresh when a new frame is ready instead of on a fixed beat. Most of the time a browser still runs at the screen's top rate and the reading is normal. Where variable refresh applies to windowed apps, though, the system may decide this page does not need every refresh, and the reading can wander or sit lower. The page calls that Unsteady and says the rate keeps moving. It is not a fault, and games running full screen still get the full range.

It can. Windows battery saver and Dynamic refresh rate, Chrome's Energy Saver, and Low Power Mode on a Mac or an iPhone may lower the refresh rate or slow page animation, sometimes to 60 or even 30 frames per second, to save power. Plug in the charger or switch the mode off and the page should note a change within a second or two.

Normally the one the browser window is on, because the browser paces its frames to that screen. With screens at different rates, some systems may pace the browser to the main display wherever the window sits, and mirrored screens usually run at one shared rate. Drag this window to the other screen: if the rate changes, the page says so. If it does not, try making that screen the main display, or reload the page after moving the window.

To save battery and keep the tab you are using responsive. A tab you cannot see has no reason to draw 144 frames a second, so browsers slow its animation sharply or pause it altogether, and some do the same for minimised or fully covered windows. That is why this page stops measuring while the tab is hidden and starts again when you come back, rather than averaging across the pause.

Refresh rate is how many times a second the screen redraws, in hertz. Frame rate is how many new images a game, video, or page produces per second, in frames per second. A 144 Hz screen showing a 60 fps game still refreshes 144 times a second, repeating some frames. Response time is something else entirely: how quickly each pixel changes colour, in milliseconds, which shows as blur or ghosting behind moving objects. This page measures the first, as the browser delivers it, and does not measure response time or input lag.

Yes. Other tabs, background apps, the system itself, and even moving the mouse over a busy page occasionally cost a frame. A handful over ten seconds reads as A few dropped frames and is nothing to worry about. What matters is a count that keeps climbing, or regular drops you can see as stutter in the motion check, which usually point to a busy computer, screen recording, or an energy saver.

For practical purposes, yes. 59.94 Hz is a rate inherited from television standards, and many screens and graphics drivers use it, or something very close, when they offer 60 Hz. The same goes for 119.88 and 120, or 143.9 and 144. The page shows the measured value and the standard rate it is closest to, and counts anything within 1.5% as that rate.

No. Frame skipping happens inside the monitor: it receives every frame but silently drops some, which some panels do when overclocked past what they can handle. The browser never finds out, so no web page can see it. Detecting it needs a camera pointed at the screen with a slow shutter, photographing a pattern that moves one step per frame. This page sees only how often the browser delivers frames.

Yes. Open the page in the phone's browser and it measures the same way. Many phones refresh at 90, 120, or 144 Hz, but they also lower the rate aggressively to save battery, and some browsers, Safari on iPhone in particular, may cap page animation at 60 Hz even on a 120 Hz screen. Low Power Mode may slow it further. A reading below the phone's specification is usually one of those caps rather than the screen.