Cleaning a monitor
A bright, even screen makes dust, smudges and fingerprints obvious. Check first, power the display off, then wipe with a dry microfibre cloth.
Refresh rate test
Run a full refresh rate test straight from your browser. Everything happens on your own device — no upload, no account, nothing installed. It works the same on a phone, a tablet, a laptop screen or a 4K desktop monitor, and it takes under a minute.
F Tap anywhere to go fullscreen
Click the screen or press F. Press Esc to exit. · 100% free. No sign-up. Works offline.
This measures how many frames per second your browser is actually presenting, by timing the gaps between animation frames and reporting the median. On a display running without interference that figure settles very close to the panel's refresh rate — about 60Hz, 120Hz, 144Hz and so on.
Give it a few seconds. The first samples are noisy while the browser settles, and the histogram below the reading shows the spread so you can see whether the rate is steady or fluctuating.
A reading well below your display's rating usually points at something other than the panel: the browser throttling a background tab, a laptop on battery saver, a variable refresh rate feature adapting to the content, or the display simply not configured at its highest mode in system settings.
What this checks
- The refresh rate your browser is actually achieving, as a median over recent frames
- Stability — a spread histogram means frames are being dropped rather than delivered evenly
- Whether the panel is configured at its rated mode rather than a default 60Hz
- The effect of power saving and variable refresh rate, both of which lower the measured figure
How to use it
Open the screen
Click or tap the preview panel. Your browser switches to true fullscreen and hides every menu bar and toolbar.
Adjust it
Use the brightness slider and the colour temperature control to get exactly the light you need. Your settings are remembered on this device.
Use it
Clean, test, light or focus. Move the mouse or tap once to bring the controls back at any time.
Exit
Press Esc, or tap the close button in the corner, to return to this page.
What people use it for
Finding dead pixels
A dead pixel stays black on white; a stuck pixel glows red, green or blue on black. Cycling solid colours is still the fastest way to find both.
Video call lighting
A white or warm-white screen beside your face fills in shadows far better than a ceiling light, and costs nothing.
Photography and video
A tablet running a solid colour makes a usable fill light, catch light or small backdrop for product shots.
Tracing and drawing
A tablet on maximum brightness under thin paper works as an improvised light table for tracing and flip-book animation.
Focus and presenting
A blank screen hides your desktop during a presentation and removes visual clutter while you concentrate.
Frequently asked questions
Is the refresh rate test really free?
Yes. Every tool on this site is free, with no account, no trial and no paid tier. You do not need to give us an email address.
Does it work on a phone or tablet?
Yes. The whole site is built mobile-first and works in Safari on iPhone and iPad, Chrome on Android, and every modern desktop browser. On iOS, fullscreen uses a full-viewport mode because Safari restricts the fullscreen API.
Does it work offline?
Yes. After your first visit the page is cached on your device, so you can open it again with no internet connection at all.
Will this damage my screen?
No. Displaying a solid colour is exactly what your screen does all day. The one caution is OLED: leaving a static bright image on an OLED panel for hours can cause temporary image retention, which is why we include an optional burn-in protection mode.
Do you collect my data?
We do not ask for a name, an email or an account, and no image ever leaves your device — every tool renders locally in your browser.
It reads 60Hz but my monitor is 144Hz.
Almost always a configuration issue rather than a fault. Check the refresh rate in your operating system's display settings, confirm the cable supports the mode you want — many HDMI cables cannot carry high refresh rates at high resolutions — and make sure the laptop is not in a power-saving profile.
Why does the number keep moving?
Browsers pace animation frames against the compositor, so the figure fluctuates slightly by nature. Large swings mean frames are genuinely being dropped, usually because another application or a background tab is competing for the GPU.
Is a browser measurement accurate?
It is accurate enough to tell 60 from 120 or 144, which is what most people want to know. It cannot be exact, because the browser sits several layers above the display pipeline and may itself be throttled.
Guides
Why Is My Screen Flickering? A Diagnostic Order of OperationsA step-by-step way to narrow screen flicker down to cable, refresh rate, driver, power or panel — starting with the checks that cost nothing.How to Check Your Screen Refresh RateHow to confirm the refresh rate your display is actually running at, why it is often lower than advertised, and how to fix it.