Refresh rate test and touch screen test

This test measures the refresh rate your monitor or phone screen is actually running at — 60, 90, 120, 144, 165 or 240 Hz — counts dropped frames and shows motion blur, like a UFO test. The second part checks the touch screen: paint every cell with your finger to find dead zones and see how many touches it detects at once.

Measurement starts by itself a second after the page opens. Everything runs in your browser — nothing to install, nothing is uploaded.

How do I check my monitor’s refresh rate?

1. Open this page on the monitor or phone you want to test. With several monitors, drag the window to the one you want.
2. Don’t scroll or switch tabs: browsers slow down rendering in background tabs, which skews the result.
3. Wait six seconds: the test shows the rate, for example “144 Hz”, and the number of dropped frames.
4. Not sure? Click “Measure again”. Being 1–2 Hz off the spec (143 instead of 144, 59.9 instead of 60) is normal, not a fault.

How the test measures refresh rate

A browser redraws the page in sync with the display and calls requestAnimationFrame before every frame. For five seconds the test records the time of each call and averages the intervals between frames: an 8.33 ms frame means 120 Hz, 6.94 ms means 144 Hz. Random hiccups don’t skew the result: long intervals are counted as dropped frames and shown separately as orange bars on the chart. That keeps the measurement accurate to a fraction of a hertz, and the result is rounded to the nearest standard rate — 60, 75, 90, 120, 144, 165 or 240 Hz.

The test shows the rate your screen is running at right now, not the one on the spec sheet. That’s the point: plenty of 144 Hz monitors spend years at 60 Hz because nobody changed the setting or the wrong cable is plugged in.

Why does it show 60 Hz instead of 144 Hz?

• The rate isn’t set in the OS. Windows: Settings → System → Display → Advanced display → Choose a refresh rate. macOS: System Settings → Displays. Android: Display → Motion smoothness or Refresh rate.
• Cable or port. HDMI 1.4 carries 4K at only 30 Hz and 1440p at no more than 75 Hz. For 144 Hz and up you need DisplayPort or HDMI 2.0/2.1. Cheap USB-C to HDMI adapters often cap the rate too.
• Power saving. Laptops on battery and phones in battery-saver mode drop to 60 Hz.
• Adaptive refresh. Phones with LTPO screens and monitors with G-Sync or FreeSync change the rate on the fly: when nothing moves it drops, sometimes to 1–10 Hz. So such a screen may measure below its maximum — that’s power saving at work, not a fault.
• Safari on iPhone and iPad. Even on a ProMotion display, Safari renders web pages at up to 60 Hz by default. Turn off the “Prefer Page Rendering Updates near 60fps” feature flag in Safari’s advanced settings to lift the cap.
• Multiple monitors. The browser syncs to the display its window is on. Drag the window to the monitor you want to test and click “Measure again”.

Dropped frames and smoothness

A dropped frame happens when the browser doesn’t finish drawing in time for the next screen refresh, so the same image is shown twice. You see it as a brief stutter while scrolling or gaming. Up to 1% dropped frames is normal. Above 5% the system can’t keep up: close heavy tabs and apps, turn off power saving and measure again. Constant drops on a powerful PC are a reason to check your graphics driver.

UFO test: motion blur and dropped frames

This is a motion blur test. Three saucers move at the same speed but update at different rates — full, half and a quarter of your refresh rate — so you can see what a high refresh rate buys you: the more often the image updates, the sharper a moving object looks. The trail behind the top saucer depends on the panel’s response time. A dark tail means a slow panel (common on VA panels in dark scenes); a bright or coloured halo means pixel overdrive is set too high in the monitor menu.

Touch test: dead zones and multitouch

1. Remove a case that wraps over the screen edges and wipe the screen.
2. Tap “Full-screen touch test” and slowly swipe over every cell, especially along the edges and in the corners.
3. Put three, four, five fingers on the screen at once — the test shows how many simultaneous touches the digitizer tells apart. 5–10 is typical. The browser and OS may limit the touch count (especially on iPhone), so the test can show fewer than the screen itself supports.
4. Close the test with ×. If the whole screen is painted, the test finishes by itself.

If cells in one area won’t turn green even after several passes, that’s a touch dead zone, and the test tells you where — “in the bottom-right corner”, for example. Remove the screen protector first: bubbles and cheap adhesive can block touch. If the zone stays, the digitizer or display module is faulty — a common result of a screen replaced with a non-original part. That’s why it’s worth running this test, and the dead pixel test, before buying a used phone.

What the test can’t check

Browsers don’t let a website read the panel’s response time in milliseconds, brightness in nits, colour gamut coverage or variable refresh support (G-Sync, FreeSync, LTPO). Check those in a review of your model. This test measures what can be measured honestly: the real refresh rate, dropped frames and touch response.

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Frequently asked questions