A number in seconds
The test starts the moment the page loads. There is no Start screen to dismiss and no 30-second wait before you see anything: the readout is live from the first frame, and the result locks after ten seconds.
About Us
About refreshratetest.app
We publish a free, private refresh rate test that measures your display's real Hz from frame timings, explains what the numbers mean, and runs entirely in your browser.
Our focus
Every frame, timed.
Time the frames, find the median, snap it to a real display rate, and show the working. That is the whole loop we design around.
- Per measurement
- 10s
- Live readouts
- 6
- Bytes uploaded
- 0
What we make
A display test that stays in the browser
refreshratetest.app answers one question well: what refresh rate is this screen actually running at right now? It is useful when you unbox a new monitor, change a cable or dock, buy a high-refresh phone, or just want to know why a game feels less smooth than it should.
The tool is the website. There is nothing to install, it works on desktop and mobile browsers, and your results history stays in local storage on your device.
The method, thresholds and readouts are documented in how the test works, and common problems are covered in the FAQ.
Background
From 60Hz CRTs to 540Hz panels
- 01
From CRTs to 500Hz
For decades, refresh rate was tied to the power grid and to broadcast standards: 60Hz in North America and 50Hz in much of the world. CRT monitors could go higher, but early flat panels settled at 60Hz. The 120Hz and 144Hz gaming monitors of the 2010s changed that, and today phones ship at 120Hz while esports panels reach 360–540Hz.
- 02
Why a browser test works
Browsers schedule animation with requestAnimationFrame, which is synchronised to the display’s vertical blank. That means the interval between frames is the display’s refresh period, so timing frames precisely measures the rate without special hardware. Pioneering browser tests such as TestUFO made this approach widely known.
- 03
This build
refreshratetest.app is an independent take on the idea. It uses a robust median-based estimate that snaps to real display rates, a ten-second run that locks a result, a live frame-time graph, a UFO-style motion check at three speeds, and a history of your results that stays on your device.
Principles
What we design around
Show the working
A single Hz figure hides a lot. We show the raw measured rate next to the snapped one, plus frame time, jitter, min/max FPS, dropped frames and a stability rating, so you can tell a slow display from a busy computer.
Private by default
Measurement happens entirely in your browser. Results are saved to local storage on your device and never uploaded. There is no account, because there is nothing to sync.
Fast on every screen
The site is static HTML with one small interactive panel. It loads quickly on a phone, never interrupts the measurement with ads or pop-ups, and fits the readout, controls and graph on one mobile screen.
Why this site
How refreshratetest.app is different
Median, not a noisy average
One slow frame does not drag the headline number down. Hitches still show up, but in dropped frames and stability, where they belong.
Clear when something is wrong
An unstable result tells you what to check. Hiding the tab throws the run away and starts again, so a throttled background tab can never produce a bogus 30Hz result.
Answers that match the tool
The guide, tips and FAQ describe this exact implementation: the 1.5× dropped-frame rule, the 3% snap tolerance and the 250 ms stall filter. Nothing is generic copy.
Contact
Found an odd reading?
Tell us the device, browser and what the test showed. Odd results on unusual hardware are how a tool like this gets better. Feature ideas are welcome too.
Get in touchMore about the tool and how we handle data: