Screen Refresh Rate Test
This test measures the refresh rate your display is actually running at, right now, in this browser window. It starts automatically — the reading below settles within a couple of seconds. A monitor sold as 144 Hz often runs at 60 Hz until you change a setting, so it is worth checking.
Measuring…
- Median frame time
- —
- Frames sampled
- 0
Multiple monitors? Drag this window onto the screen you want to test — the browser renders at the rate of the monitor it is on.
Reading lower than your monitor's rated Hz? Fix a monitor stuck at 60 Hz →
How this refresh rate test works
The browser paints new frames in sync with your display — one animation frame per screen refresh. This test timestamps every frame the browser delivers, filters out hiccups (a tab switch, a heavy background task), and takes the median time between frames. 1000 divided by that frame time is your refresh rate: 16.7 ms per frame means 60 Hz, 6.9 ms means 144 Hz. Everything runs locally in your browser — nothing is uploaded.
Testing a new monitor? Also try the ghosting test to check motion clarity, and the dead pixel test for panel defects.
Frequently asked questions
Why does it show 60 Hz when my monitor supports 144 Hz?
The most common reason: the operating system is set to 60 Hz. On Windows, check Settings → System → Display → Advanced display and pick the highest refresh rate; on macOS it is in System Settings → Displays. Also make sure the browser window is on the monitor you want to test — with several monitors, the browser renders at the rate of the screen the window is on. Finally, some cables and laptop power-saving modes cap the rate.
Why does the measured number fluctuate slightly?
The browser reports frame timestamps with limited precision, and background work on your machine adds jitter. This test uses the median of a rolling window of frames, so the reading settles within a couple of seconds. Small fluctuations around a common value (e.g. 143.8–144.2) mean your display is running at that rate.
Does this measure my monitor or my graphics card?
Neither in isolation — it measures how fast the browser actually receives new frames, which is the refresh rate the operating system is driving your display at. That is usually what you want to know: it reflects the monitor, the cable, the GPU settings and any power-saving caps combined.
My iPhone or iPad has a 120 Hz ProMotion display but the test shows 60 Hz. Why?
Safari renders web content at 60 Hz unless the page is allowed to run at the full rate. On iOS you can enable full 120 Hz for web content under Settings → Apps → Safari → Advanced → Feature Flags (the flag name varies by iOS version). Low Power Mode also caps the whole system at 60 Hz.
What refresh rate do I need?
60 Hz is fine for office work and video. 120–165 Hz makes scrolling and gaming visibly smoother and is the sweet spot for most people. 240 Hz and above mainly benefits competitive fast-paced gaming. Note that video content at 24/30/60 fps does not get smoother on a faster display.