When a CPS test misbehaves, the cause is almost always one of a few things: a browser setting, an extension, the computer being busy, or the mouse itself. This guide goes through each symptom, explains what causes it, and shows you how to fix it.
Work through the sections that match your problem. If nothing helps, the last section explains how to report it to us.
Quick checks before anything else
These four checks fix most problems in under a minute:
- Reload the page. Press Ctrl + F5 on Windows or Linux, or Cmd + Shift + R on a Mac, to load a fresh copy.
- Update your browser. Old browser versions may not support the timing features the test uses.
- Try a private window. Extensions are usually off in private mode, so this quickly shows whether an extension is the problem.
- Try another browser. If the test works in a different browser, the issue is in the first browser's settings or extensions.
The timer does not start
Cause: JavaScript is off or blocked
The click counter runs on JavaScript. If it is disabled, the page still loads and you can read the guides, but the console shows a message asking you to enable JavaScript.
Fix
- In Chrome or Edge, open Settings → Privacy and security → Site settings → JavaScript and allow it.
- In Firefox, JavaScript is controlled by the
javascript.enabledsetting on theabout:configpage; it should betrue. - In Safari on Mac, open Settings → Security and tick Enable JavaScript. On iPhone, go to Settings → Apps → Safari → Advanced.
- If you use a script blocker such as NoScript or uBlock Origin in advanced mode, allow scripts on this site.
Some clicks are not counted
If your click count feels lower than the number of times you pressed, check these causes in order.
Clicking outside the pad
Only clicks inside the dark click pad count. When clicking fast, the pointer can drift. Start in the centre and keep your hand still apart from your finger.
A busy computer
If a game, video export or many tabs are running, the browser may not process every event instantly. Close heavy programs and test again.
Trackpad tap detection
Tap-to-click can ignore taps that come very close together. Press the trackpad down physically or use a mouse.
A failing mouse switch
Mouse switches wear out. A worn switch may not register every press. Test with a different mouse; if the problem disappears, the original mouse is the cause.
Click slowly ten times while watching the counter. If it shows fewer than ten, the issue is your hardware or setup, not your speed.
One click counts as two
If a single press sometimes adds two to the counter, you are almost certainly seeing switch bounce, often called a double-click fault. As switches age, their metal contacts can bounce and send two signals for one press.
How to confirm it
1. Choose the 60s test so you have plenty of time 2. Click slowly, about once per second, 20 times 3. If the counter shows more than 20, your switch is double-clicking
What to do
- Check your mouse software for a debounce time setting. Increasing it slightly can hide the fault.
- Check your warranty — double-clicking is a common warranty repair.
- Replace the mouse or, if you are comfortable soldering, replace the switch.
A double-clicking mouse inflates your CPS. Scores from a faulty mouse are not a fair comparison with anyone else's.
Problems on phones and tablets
| Symptom | Likely cause | Fix |
|---|---|---|
| Page zooms in | Taps landed outside the pad | Tap only inside the pad; rotate to landscape for a bigger target |
| Text gets selected | Long press outside the pad | Keep taps short and inside the pad |
| Taps are missed | Very light touches or a screen protector | Tap firmly; check the protector is not lifting |
| Counter freezes | Low-power mode throttling the browser | Turn off battery saver while testing |
Swipe sideways to see the whole table.
Some phones also have gesture navigation that reacts to swipes near the edges. Keep your taps near the centre of the pad.
The counter stutters or lags
A jumpy counter usually means the browser is not getting enough processing time.
- Close other tabs, especially video and games.
- Plug in your laptop — many laptops slow down on battery.
- Turn on hardware acceleration: in Chrome or Edge this is under Settings → System.
- Disable extensions that inject scripts into every page.
Your final score is calculated from the exact time of each click, so a slow display does not usually change the result. But a struggling computer can still miss clicks, so it is worth fixing.
Check your mouse and system settings
Some settings on your computer or in your mouse software can quietly change how clicks are registered.
Mouse software
- Macros and rapid-fire. If a macro or "turbo" mode is assigned to the left button, it will add clicks you did not make. Turn it off or switch to a default profile.
- Debounce time. Some gaming mice let you change how long the mouse waits before accepting another click. A very long debounce can ignore fast clicks; a very short one can let switch bounce through as double clicks.
- Polling rate. Common settings are 125, 500 and 1000 Hz. Higher rates report movement more often, but any of them is fast enough to register normal clicking.
Operating system
- ClickLock (Windows). In the classic Mouse settings, ClickLock lets you "hold" the button by pressing briefly. If it is on, fast clicks may behave strangely. Turn it off while testing.
- Mouse Keys and accessibility tools. Features that control the pointer from the keyboard or add click assistance can interfere. Disable them temporarily if you do not rely on them.
- Remote desktop and screen-sharing apps. Clicking through a remote session adds delay and can drop events. Test on the computer itself.
If you rely on accessibility settings, keep them on. The keyboard option on the click pad — Space or Enter while it is focused — is there so everyone can take the test.
Does the browser make a difference?
All modern browsers handle clicks quickly enough for a CPS test, so your choice of browser should not change your score in any meaningful way. Differences you notice usually come from what is running inside the browser rather than the browser itself.
- Extensions. Ad blockers, mouse-gesture tools, auto-refreshers and page translators can all add work to every click. Test once with extensions disabled to compare.
- Profiles. A browser profile with dozens of tabs restored at start-up competes for memory. A fresh profile or private window is a clean baseline.
- Zoom level. Zooming in or out does not change counting, but a very large zoom can push the pad partly off-screen on small displays. Press Ctrl + 0 (or Cmd + 0) to reset.
If you see a big difference between two browsers on the same computer, the slower one almost always has an extension or setting worth investigating.
Missing history and how to report a bug
My recent results disappeared
Results are saved only in your browser's local storage. They disappear if you use a private window, clear site data or switch browsers. We never receive your scores, so we cannot restore them.
Reporting a bug
If none of the fixes above help, contact us. To help us find the issue quickly, include:
- Your device and operating system (for example Windows 11, Android 15).
- Your browser and version.
- What you expected and what actually happened.
- Whether it also happens in a private window.
Frequently asked questions
The clicking engine runs in JavaScript. Enable it in your browser's site settings or allow scripts in your blocker, then reload.
It is usually a worn switch rather than a completely broken mouse. Increasing debounce time may help, but replacement or a warranty repair is the long-term fix.
The score uses precise click timing, so a slow display alone rarely matters. A heavily overloaded computer can miss clicks, though, so close heavy programs for the best result.
No. Results are stored only in your browser and never sent to us. Clearing site data or using a private window removes them.
Key takeaways
- Reload, update your browser and try a private window to rule out simple causes.
- The test needs JavaScript; allow it for this site if the timer will not start.
- Clicks only count inside the pad — keep your pointer centred.
- A counter that jumps by two on one press points to a worn mouse switch.
- Results are stored only in your browser, so private windows and clearing data remove them.