Measurements are performed only within the browser, and measurement values and device information are not sent or saved to the server. The Hz to display is requestAnimationFrame is the effective drawing cycle of the browser estimated from The nominal specification values of the display itself are not obtained directly.

Measurement settings

Warm up for 3 seconds before measuring and tally the drawing interval for the selected time.

Measurement time Criteria for missing detection Hz Show motion examples Suppress sleep during measurement

Condition: Ready Progress: 0.0 / 10 seconds Tab: Displaying Display: Normal display Sleep suppression: Valid after measurement starts Long Task: 0 items / 0.0 ms

Rendering test

Since the moving marker moves based on elapsed time rather than the number of frames, stutters and uneven updates are visible.

Ready Measures the browser drawing cycle

Measurement results

Uses the median for the primary Hz estimate and estimates dropped frames from the selected or automatically estimated reference Hz.

frame time graph

Displays the time transition and distribution for each frame. The farther the line moves upward, the longer the drawing stop is.

to measure correctly

Set your power mode to prioritize performance, then close unnecessary videos, games, and heavy tabs before measuring.
For external displays, check that the desired refresh rate is selected in the OS screen settings.
If you change the full screen display or the connected display, the drawing conditions will change, so the tool will start the measurement again from warm-up.
When a tab is hidden, the browser suppresses drawing, so the measurement results are invalid while the tab is hidden.
Measurements will vary on the same display due to variable refresh rates, power management, and browser load.
If you feel any change in your physical condition due to strong movements, please stop the measurement and turn off "Show movement samples".

About this tool

You can check whether the display and browser drawings are updated at the expected frequency from the trends and distribution of effective Hz, FPS, and frame time.

Features

10 seconds/30 seconds measurement, 3 seconds warm-up, effective Hz, FPS, median, P95, P99, jitter, missing frame estimation
Frame time graph, distribution graph, moving marker, full screen display, sleep suppression, result copy

How to use

Select the measurement time and the reference Hz for missing detection.
Press "Start measurement" and wait while the tab is displayed.
Check the estimated Hz, FPS, frame time, stability and graphs.

Limitations

The displayed Hz is the browser's effective rendering interval estimated from requestAnimationFrame; it does not directly obtain the display panel's nominal specification.
Measured values will fluctuate depending on variable refresh rate, OS/browser power management, and load of other tabs and apps.

Privacy: Frame time collection, aggregation, and graph drawing are performed within the browser, and measurement values and device information are not sent or saved to the Develop Tools server.