At 60 frames per second, a new image arrives roughly every 16.7 milliseconds when delivery is even. A test of frame delivery can reveal whether that timing holds. A frames-per-second check also helps you compare motion at different rates, but the display’s refresh setting determines how often the screen can update.
These numbers describe different stages of playback. A high average can coexist with visible stutter if individual frames arrive unevenly. To interpret the result, compare the animation, the reported rate, and the display setting under the same conditions.
Frames per Second Test: What the Numbers Mean
Frame rate, measured in frames per second (fps), describes how many images an application or video produces or presents each second. Refresh rate, measured in hertz (Hz), describes how often a display refreshes each second. At a fixed 60 Hz, a refresh takes about 16.7 milliseconds; at 120 Hz, it takes about 8.3 milliseconds.
A 120 fps source on a 120 Hz display can supply a fresh frame for each refresh when timing and synchronization align. A 60 fps source on the same display may show each frame for two refreshes. Conversely, a 60 Hz screen cannot display 120 distinct full-screen updates each second. Depending on synchronization, it may show repeated frames, skip opportunities to show some frames, or show portions of different frames as tearing.
A higher refresh rate gives motion more opportunities to update. It does not create detail that is absent from a lower-frame-rate video. A movie encoded at 24 fps still contains 24 source frames per second unless processing generates intermediate frames.
Prepare a repeatable comparison
First check the selected refresh rate in your operating system’s display settings. Select the screen you are testing and note its resolution and refresh rate. A monitor advertised for 144 Hz may be running at 60 Hz because of a setting, connection, adapter, or resolution limit. Check the monitor and connection specifications before assuming the higher mode is available.
Open a browser-based motion comparison, such as TestUFO’s multiple-framerate display. Keep the test on the intended monitor, close other demanding applications and tabs, and wait for its status to settle. Note browser warnings: browser scheduling, hardware acceleration, power saving, and the window’s display can affect the result.
Run the frame test with the same browser, screen, resolution, and refresh setting each time. Record the displayed rate and any warnings alongside what you see. If you change a setting, repeat the same sequence so you can identify which change affected the result.
Compare motion at 60, 120, and 144 fps
Start with a 60fps test and follow the moving object with your eyes. Look for evenly spaced motion and note whether the image appears to jump. Then select a higher available rate while keeping the motion speed and display setting consistent. Following the object helps reveal the continuity of movement; it does not independently measure the actual frame rate.
A 120 fps test is meaningful only if the screen and test path can present that rate. On a display set to 120 Hz or above, compare it with the 60 fps animation at the same speed. You may see smaller steps between positions. If the tool reports a lower output, use that reported value when interpreting the comparison.
A 144 fps test needs a display mode and a test capable of reaching that rate. If your monitor is set to 120 Hz, a requested 144 fps animation cannot produce 144 distinct full-screen updates per second on that fixed-refresh display. Compare at a supported mode and check the tool’s measured result, rather than treating the selected option as a measurement.
An average alone can hide short interruptions. A rate of 120 frames per second across one second could include a pause followed by a burst. When the tool provides frame-time information, look for spikes: a frame taking much longer than its neighbors can appear as a hitch even when the average looks high.
Check refresh rate and skipped refreshes
A 120hz test typically checks whether the browser estimates a refresh rate near 120 Hz. Compare that estimate with the operating system setting. A small rounding difference is less informative than a sustained result near 60 Hz when you selected 120 Hz. The browser estimate is a timing observation, not a direct inspection of every physical panel refresh.
For suspected display frame skipping, use a dedicated test such as TestUFO’s frame-skipping checker. Wait for its ready indicator, then photograph the pattern with a camera using an exposure of 1/10 second or longer, following the page’s instructions. The photo should capture several consecutive squares. Gaps in the sequence can indicate skipped refreshes; a screenshot cannot capture this physical display behavior.
If the pattern has gaps, return an overclocked display to a supported standard refresh setting and repeat. Try another supported cable or port if the issue remains, and record the configuration. This test addresses skipped refreshes; it does not by itself diagnose the cable, graphics hardware, or panel.
Why results may not match
A framerate tester measures the workload and timing of its own animation. A demanding game, editing preview, or video player can behave differently because its rendering, decoding, and synchronization demands differ. Check the application’s own performance overlay or dropped-frame statistics when the problem occurs there.
If a browser test falls short, confirm the selected refresh rate and the connection’s supported mode. Close background workloads, check that hardware acceleration is enabled, and repeat with the browser on the correct monitor. On a laptop, compare plugged-in operation with battery mode; power settings can change performance. Change one factor at a time and note the result.
Variable refresh rate can adjust the display’s timing to match changing output within its supported range. V-sync and frame caps also affect delivery and tearing. Record their settings when comparing a game with a browser demonstration, because they may not use the same presentation path.
Now open a frames per second test, write down the configured refresh rate and reported frame rate, and watch one animation at 60 fps. Repeat at your display’s higher supported rate. If the reported number or motion is unexpected, start by checking the selected display mode and rerun the comparison.
