Test your input devices in real time. Capture mouse click and scroll events plus keyboard key press counts, then copy or export reports.
Click and scroll inside this test area to capture left, right, and wheel activity.
Mouse & Keyboard Tester is a free browser-based tool that lets you verify every input on your mouse and keyboard in real time. It tracks left and right clicks, scroll wheel activity, individual key presses, and unique key counts so you can quickly diagnose sticky buttons, unresponsive keys, or double-click issues. Whether you are troubleshooting a new peripheral or stress-testing gaming hardware, this tool gives you the data you need without installing any software.
Yes. Any mouse or keyboard that your operating system recognizes will work with this tester. It captures standard browser input events, so it is compatible with wired, wireless, Bluetooth, and USB peripherals across Windows, macOS, and Linux.
No. All testing happens locally in your browser. Click counts, key presses, and scroll data are stored only in your current session memory and are never transmitted to any server. Closing or refreshing the page clears everything.
The tester reliably captures left click, right click, and scroll wheel events. Additional side buttons on gaming mice may or may not fire standard browser events depending on your mouse driver configuration. Standard left, right, and middle click buttons are fully supported.
Certain key combinations like Ctrl+W or Alt+F4 are intercepted by your browser or operating system before they reach the page. Individual keys and most standard shortcuts will register normally. If a specific key does not appear, try pressing it on its own first.
After completing your test, click the Copy Data button to copy a summary to your clipboard, or use Export Data to download a text file. You can then paste the summary into an email or attach the file to a support ticket.
A mouse and keyboard tester is a browser-based diagnostic tool that captures and visualizes raw input events from your physical devices in real time. Every key you press, every mouse button you click, and every scroll wheel movement is intercepted by the browser's event API and displayed on screen — letting you verify that your hardware is registering input exactly when and how you expect it to. Unlike software-level testing that might be influenced by drivers or operating system settings, a browser-based tester gives you a clean, neutral environment to isolate whether a problem is in the hardware itself.
For keyboards, the most important thing to test is ghosting — a phenomenon where pressing multiple keys simultaneously causes some of them to go unregistered because the keyboard's matrix circuit can't distinguish them. This is particularly important for gaming, where pressing WASD plus Shift plus Space simultaneously is routine. High-end gaming keyboards advertise "N-key rollover" (NKRO), meaning every key is detected independently no matter how many others are held. This tester lets you verify those claims by pressing combinations and watching which keys actually register. For mice, you can confirm click registration, detect double-click faults (a common failure in switches after heavy use), and verify side button mapping.
Mouse DPI (dots per inch) describes the sensitivity of the optical or laser sensor — how many pixels the cursor moves per inch of physical movement. A higher DPI means faster cursor movement at the same physical speed. Professional gamers often use surprisingly low DPI settings (400–800) for precision, while general productivity users might prefer 1200–1600 for comfortable navigation across large monitors. If your mouse has DPI adjustment buttons, you can use this tester alongside your OS cursor speed settings to find the ideal feel. Hardware problems like sticky switches, drifting sensors, and chattering buttons are all diagnosable here before you spend money on a replacement.
Keyboard ghosting happens when you press three or more keys at the same time and one or more of those key presses fails to register. It's a hardware limitation of traditional keyboard matrix circuits, where the electrical design can't distinguish certain simultaneous inputs. The phantom keys that do get registered incorrectly are called "ghost keys." Gaming keyboards address this with anti-ghosting circuitry or full N-key rollover (NKRO), where every key has its own dedicated scan line. To test for ghosting, press the key combinations you use most often and watch whether all of them light up in the tester.
A stuck key will show as permanently highlighted in the key display even when you're not pressing it — this is the browser receiving a continuous keydown event with no corresponding keyup. A failing key will show no response at all when pressed, while surrounding keys work normally. Intermittent failures are trickier: rapidly tap the suspect key 20–30 times and watch for any missed registrations. If roughly the same key keeps missing, the switch is wearing out. Mechanical switches can often be fixed by cleaning with compressed air or isopropyl alcohol; membrane switches are generally not repairable.
Mouse debounce is a firmware-level delay built into the mouse that filters out spurious extra signals when a button is clicked. Physical switches "bounce" — they make and break contact multiple times in rapid succession during a single click, on the order of milliseconds. Debounce logic waits a few milliseconds before registering a second click, treating the bounce as noise. If the debounce time is too long, your mouse will feel sluggish in fast clicking scenarios. If the switch wears out and bounces longer than the debounce window, you'll get double-click registration from a single physical press — a classic sign of a dying mouse switch.
Double-clicking on a single press is almost always caused by a worn or faulty micro-switch inside the mouse button. You can confirm it with this tester — perform single, deliberate clicks and watch if the click indicator flickers twice. Software workarounds exist: Windows has a "double-click speed" setting that can reduce sensitivity, and some mouse firmware tools let you increase the debounce delay. The permanent fix is replacing the micro-switch, which is a soldering job possible on most mice, or claiming warranty replacement. Logitech mice are particularly well-documented for this repair online.
This tester is ideal for verifying a keyboard after it arrives — use it immediately on unboxing to check every key before the return window expires. For testing before buying, your best resource is typing-focused review sites and switch tester sample packs if you're choosing between switch types. However, if you're buying from a local store or a second-hand marketplace, pulling up this tester on your phone and typing on the display unit or used keyboard is an excellent way to catch dead keys or ghosting issues on the spot. Just navigate to this page in your mobile browser and connect a USB keyboard if testing wired models.
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