Screen Refresh Rate Test
UFO Test: measure your live refresh rate and frame rate.
Press start and watch how smoothly the little UFO flies — that is your refresh rate.
Why this tester
Intuitive UFO comparison
The UFO Test is the classic subjective refresh-rate check: a little saucer glides across the screen and your eyes judge the smoothness instantly — no expertise required.
Three speeds on one screen
Full, 1/2 and 1/4 rate UFOs fly together, so the stutter of low rates and the glide of high rates can be compared directly, side by side.
Live data panel
A rAF frame counter reports the current rate, peak rate and stability percentage live, plus automatic resolution, GPU and OS detection.
Install-free, cross-platform
Built on native browser APIs — runs on Windows, macOS, Android and iOS out of the box, with black/white backgrounds and an immersive mode that works even on iPhones.
How the UFO Test works
- 01 · Start the test
Press Start and watch the little UFO glide across the screen; enable the 1/2 and 1/4 rate simulations to compare high vs low refresh rates side by side.
- 02 · Judge smoothness
The smoother the UFO flies, the higher your refresh rate. Visible stutter, jumping or ghosting points to a low rate or slow pixel response.
- 03 · Read the data and adjust
The page shows the live rate, peak rate and stability; set your display to its highest supported refresh rate in system settings for the best experience.
Frequently asked questions
What is a refresh-rate comparison test?
It simulates lower refresh rates so you can see the difference directly: the 1/2 and 1/4 rate UFOs visibly jump and stutter, showing exactly what refresh rate does to the experience.
Why is my result unstable?
Assuming hardware and cabling are fine, system load and browser performance can skew it. If a professional tool disagrees, trust the professional tool.
How do I raise my refresh rate?
Change it in system display settings, keep GPU drivers up to date, and use a high-refresh panel with a capable cable (DP 1.4 / HDMI 2.1).
Is some ghosting normal?
Slight ghosting is normal. Heavy trails suggest a low refresh rate or slow pixel response — try enabling the monitor’s Overdrive setting.
Does it work on phones?
Yes — the tool runs on Windows, macOS, Android and iOS, though some mobile browsers cap the frame rate; cross-check with the rate stated in system settings.
Does the browser matter?
Yes. Rendering engines differ; use a modern browser like Chrome or Edge with power saving and heavy background apps off.
Refresh rate basics
Key concepts
- Refresh rate (Hz): how many times per second the display redraws — higher means smoother, more continuous motion.
- FPS: frames per second the GPU renders; match it to the refresh rate or you get tearing/stutter.
- Response time: pixel color-switch time — independent of refresh rate; slow response still causes ghosting.
- Input lag: the time from your input to the frame appearing on screen.
Common tiers
- 60Hz: baseline — fine for office and web use.
- 75–100Hz: a light boost you can feel.
- 120–144Hz: the mainstream sweet spot for gaming and phones.
- 165–240–360Hz: top-tier for competitive FPS players.
Specs don't always equal reality — cables, drivers and system settings can quietly lower your actual refresh rate. Verify it with a tester.
How refresh rate affects smoothness
Why high refresh feels smoother
- Our brains fill short gaps between frames into continuous motion — that's why 24fps film still looks fluid.
- Fast-moving objects (game crosshairs, mouse cursors) expose the "position jump" between frames.
- A higher refresh rate shortens those gaps, so moving objects are easier to track precisely.
Tearing, stutter & sync
- Screen tearing: FPS exceeds refresh with no sync — a frame is pushed before the panel finished the last one.
- Stutter: FPS below refresh — frames arrive unevenly and feel janky.
- V-Sync, G-Sync / FreeSync and VRR make the refresh rate follow the frame rate; LTPO does the same on mobile to save battery.
- Use the tester to confirm sync is actually working — it's hard to judge by eye.
Refresh rate needs by scenario
By content
- Office / static: 60Hz is plenty; paying more for high refresh helps little here.
- Movies: content is mostly 24–30fps — above 60Hz gains are small; color/contrast matter more.
- Productivity: scrolling, dragging and cursor motion feel clearly smoother at 90–120Hz.
- Competitive gaming: 144–240Hz+ translate into faster reactions and more precise aim.
By device
- LCD: refresh rates are usually fixed — set the top tier manually in system settings.
- OLED: self-emissive pixels respond fast, keeping high refresh with crisp motion.
- Mobile (LTPO): the refresh rate adapts on the fly (down to 1Hz for static content, up to 120Hz when scrolling), so average use can be lower than the labelled peak.
Checking & troubleshooting refresh rate
How to judge if it's normal
- Noticeable tearing on fast lateral motion usually means sync is off or the rate is mis-set.
- Compare the system display setting with the panel's rated spec; systems often default to a lower rate.
- Ghosting or stutter when scrolling can come from refresh, response time or frame-rate mismatch.
Common causes of a "shrunk" refresh rate
- Cable/interface limits — e.g. HDMI 1.4 can't carry 144Hz@2K+; use HDMI 2.0+ or DP.
- GPU drivers not recognizing the panel's top rate.
- Laptop power-saving mode dropping to 60Hz.
- An in-game FPS cap below the panel's refresh rate.
A tester shows the true refresh in real time — much more reliable than guessing by eye.
Refresh rate optimization tips
Set it in the system
Windows: Settings → Display → Advanced → refresh rate; macOS: System Settings → Displays. Always double-check after connecting a new monitor.
Cables and ports
High refresh needs bandwidth: DP 1.4 does 4K@144Hz, HDMI 2.1 does 4K@120Hz+. A cheap or legacy cable is the most common cause of a locked 60Hz.
Keep drivers fresh
GPU driver and monitor firmware updates often unlock new high-refresh modes; the NVIDIA/AMD control panels also allow per-app refresh overrides.
In-game sync
Enable G-Sync / FreeSync in games and cap the frame rate at the refresh rate to eliminate both tearing and stutter.
Phone prep
Disable power saving and close heavy background apps before testing; iPhones may cap web pages at 60Hz — trust the rate stated in system settings.
Buying & verification guide
Pick by use case
- Office/typing: 60–75Hz is enough.
- Light gaming/multitasking: 100–120Hz balances smoothness and value.
- Competitive gaming (FPS/MOBA): start at 144Hz; go 165/240Hz on a bigger budget.
- Pro-level play: 360Hz+ — but you need a strong GPU to actually hit the numbers.
Don't ignore these details
- Cable/interface bandwidth: confirm HDMI 2.0/2.1 or DP 1.2+ handles your resolution + refresh target.
- Adaptive sync (G-Sync / FreeSync / VRR) is a big win for smooth gaming.
- Balance refresh rate with response time — a fast refresh with slow pixels still ghosts.
Verify what you buy
- Right after setup, run the tester to confirm the real rate matches the spec.
- Check whether the system recognizes the max rate and it stays stable under static/sliding/gaming content.
- Use the result to tune drivers and settings so the number on the box becomes what you actually see.