Device tests · Display
Refresh Rate Test
This refresh rate test estimates how often your browser is delivering new frames to this page. It times about four and a half seconds of animation frames, ignores a short warm-up, and turns the median frame interval into an observed rate in hertz.
The result reflects the cadence the browser is presenting at, which usually follows the display's current refresh mode. It does not read your monitor's specification or EDID data, and a single run is not proof of a hardware setting or fault.
- About 5 seconds
- Median frame timing
- Starts only when you press
Estimate your browser frame rate
Keep this tab visible and avoid moving windows for about 5 seconds. The page times the frames the browser delivers; it does not read your monitor's specification.
Observed refresh estimate
Not measured yet- Estimated rate
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- Median frame time
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- Frames measured
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- Late / long frames
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This estimates the cadence your browser is presenting frames at. A low result is not proof of a hardware fault.
Your result
What your result means
Refresh rate is how many times per second a display can show a new image. At 60 Hz a new frame is possible every 16.7 ms; at 120 Hz every 8.3 ms; at 144 Hz about every 6.9 ms; at 240 Hz about every 4.2 ms. Higher rates can make scrolling, cursor movement and fast motion look smoother when the content and system keep up.
If your estimate is close to the rate you selected in your display settings, the browser is likely presenting at that mode. If it is lower, the cause is often a setting, cable, power mode or browser behaviour rather than a broken monitor — check those before drawing conclusions.
- Estimated rate: 1000 divided by the median frame interval. It is shown with one decimal place and is not rounded to a marketing figure.
- Median frame time: the middle frame interval in milliseconds, which resists occasional long gaps.
- Frames measured: how many intervals contributed after the warm-up. Very few frames make the estimate unreliable.
- Late / long frames: intervals longer than 1.5× the median, usually caused by system load. They are counted but do not drag the estimate down.
- Consistency: a simple reading of how tightly intervals clustered around the median.
Procedure
How the test works
- 01
Prepare
Close heavy apps and keep this tab in front. On a laptop, plug in power if possible, because battery saving can lower the rate.
- 02
Start the test
Press “Start Refresh Rate Test”. Nothing runs until you press it.
- 03
Wait without switching tabs
Leave the window still for about five seconds. If the tab is hidden, the run is cancelled and marked unreliable.
- 04
Read the estimate
Check the estimated rate, median frame time and consistency note.
- 05
Run it again
Repeat two or three times. Similar results are more meaningful than a single run.
Methodology
How Testpartout measures this
The test uses requestAnimationFrame, the browser's frame callback, and records the high-resolution timestamp it supplies for each frame.
What the implementation does
- Measurement starts only from a button press and runs for 5 seconds in total: the first 0.5 seconds are a warm-up and are discarded.
- Consecutive timestamps are converted into frame intervals. The median interval is used because a few delayed frames barely change it, whereas an average would be pulled down.
- Observed rate = 1000 ÷ median interval in ms.
- Consistency combines the median absolute deviation of intervals (relative to the median) with the share of frames longer than 1.5× the median.
- A nearby common rate (such as 60, 120, 144 or 165 Hz) is mentioned only when the estimate is within 3%, as context rather than a verdict.
- If the page becomes hidden or is left during a run, the loop stops, the samples are discarded and you are asked to restart.
Limits of a browser measurement
- The test estimates browser frame cadence. It cannot read EDID, manufacturer specifications or the monitor's maximum supported rate.
- Browser scheduling, power saving, background load, compositor behaviour and throttling can all change results.
- With variable refresh rate (VRR) such as adaptive sync, the cadence can follow content rather than a fixed mode.
- On systems with several monitors at different rates, browsers may synchronise to one display.
- A low or unusual result is not proof of a hardware fault.
Privacy
What happens to your data
This section describes the behaviour of the code on this page, not an intention.
- No permission is needed. Frame timings stay in this page's memory and are discarded when you leave.
- No refresh rate, frame time or consistency value is saved, uploaded or sent to analytics.
- Only consent-controlled start and complete events, with no measured values, may be recorded.
Troubleshooting
If the test does not behave as expected
It shows 60 Hz on a high-refresh monitor
Check the refresh rate selected in your operating-system display settings; many systems default to 60 Hz. Also confirm the cable and port support the higher rate at your resolution.
Results change between runs
Background activity, power mode and browser scheduling vary from moment to moment. Close other apps, keep the window still and compare several runs.
Laptop result is lower on battery
Power-saving modes can reduce the display rate or throttle the browser. Plug in and select a performance or balanced power mode, then re-test.
The run was cancelled
Switching tabs, minimising the window or locking the screen hides the page and pauses frames. Keep the tab visible for the whole run.
Result is between common rates
Variable refresh, fractional modes such as 59.94 Hz, or irregular scheduling can produce in-between values. Turn off VRR temporarily if you want a fixed-rate reading.
Wrong monitor in a multi-display setup
Move the browser window onto the monitor you want to check and run again; the browser may follow one display's timing.
Factors
What can change the observed rate
The browser sits between the display and this page. These factors affect what the page can observe.
Display settings
The selected refresh mode in the operating system usually sets the ceiling the browser can reach.
Cable and port
Some cables, adapters and ports cannot carry high refresh rates at high resolutions, so the system may fall back to a lower mode.
Power saving
Battery and eco modes can lower the display rate or slow the browser's frame loop.
Browser throttling
Background tabs, embedded frames and some low-power situations receive fewer or no animation frames.
Variable refresh rate
Adaptive sync lets the display follow the content's frame rate, so a light page may not show a fixed maximum.
System load
Heavy CPU or GPU work can delay frames. The median resists this, but very busy systems still reduce consistency.
FAQ
Frequently asked questions
- What is my refresh rate?
- Run the test to see the rate your browser is currently presenting frames at. To confirm the configured mode, check your operating system's display settings, which list the selected refresh rate.
- Why does 60, 120, 144, 165 or 240 Hz matter?
- A higher refresh rate gives the display more opportunities per second to show a new image, which can make motion, scrolling and cursor movement look smoother when the system can render that fast.
- Why can a browser measurement differ from my monitor's spec?
- The browser measures its own frame delivery. Display settings, cables, power saving, variable refresh, other monitors and browser scheduling can all mean it runs below the panel's maximum.
- Why did the result change between runs?
- Background load and browser scheduling vary over time. Compare several runs with other apps closed and the window still; a consistent result is more meaningful than one reading.
- Does a low result mean my monitor is broken?
- No, not by itself. Check the selected refresh rate, cable, port, power mode and VRR settings first. Contact the manufacturer only if the setting is correct and problems persist in other software.
- Does this test read my monitor's EDID or specifications?
- No. Web pages cannot access EDID or hardware specifications. The test only times animation frames inside the browser.
- Why does the test ignore the first half second?
- Frame timing is often irregular right after an animation starts. Discarding a short warm-up gives a steadier estimate.
- Are my results uploaded?
- No. Measured values stay on this page. If you consent to analytics, only the start and completion of the test are recorded, without any values.
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