Free 100% In-Browser Tool

Mouse Tester: Test Left, Right, Middle & Side Buttons Online

Inspect mouse buttons, scroll wheel encoders, side navigation buttons, and double-click actuation in an interactive testing canvas.

Quick Answer:Click and scroll anywhere on the test canvas. The virtual mouse graphic illuminates each pressed button and tallies scroll ticks in real time.

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Privacy First: 100% Client-Side Processing

Processed in your browser. Files are never uploaded.

How to Use the Mouse Tester: Test Mouse Buttons, Scroll Wheel & Clicks

1Move your mouse cursor into the designated testing area.
2Click your left, right, and middle mouse buttons to verify switch actuation.
3Scroll your mouse wheel up and down to check optical/mechanical wheel encoder ticks.
4Press your thumb side buttons (browser back and forward) to verify auxiliary buttons.

Formula & How It Works

W3C Pointer & Mouse Event Standards

Button Registration: event.button ∈ {0, 1, 2, 3, 4} | Delta: Math.sign(event.deltaY)

Detects hardware button indices (0 = Left, 1 = Middle, 2 = Right, 3 = Back, 4 = Forward) and wheel delta directions. Source: W3C Pointer Events Specification.

Worked Examples

Testing Primary Left Click

Input: User presses physical left click button

Explanation: Confirms main microswitch electrical contact.

Result: Virtual Left button turns blue; last action: 'Mouse Button Pressed: LEFT (Button 0)'

Testing Scroll Wheel Encoder

Input: User rolls wheel downward 3 notches

Explanation: Verifies the mouse scroll wheel rotary encoder is registering movement.

Result: Scroll direction: DOWN, Scroll count incremented by 3

Detecting Double-Click Switch Fault

Input: User single clicks but a worn switch bounces twice

Explanation: Helps identify worn mechanical microswitches experiencing debounce failure.

Result: Double click count immediately registers > 0

Frequently Asked Questions

Can this tool test mouse side thumb buttons?▼

Yes, side buttons 3 (Back) and 4 (Forward) are fully supported and will illuminate on the virtual mouse body when pressed.

How do I know if my mouse has the double-clicking issue?▼

Click gently and slowly once on the test pad. If the 'Double Clicks' counter increments on a single physical finger press, your microswitch has developed debounce wear.

Can this tool measure mouse DPI or polling rate?▼

No. Standard browser security sandboxes do not expose raw USB polling interrupts (e.g. 1000 Hz) or physical hardware DPI counts. This tool focuses on switch actuation and encoder integrity.

Why doesn't right-click open a context menu here?▼

We intentionally prevent the default context menu inside the canvas so you can test right-click switch actuation freely without popup interruptions.

Does this tester work with Apple Magic Mouse and trackpads?▼

Yes, single clicks, secondary taps, and two-finger scroll wheel events are accurately registered.

How can I fix a skipping scroll wheel?▼

Scroll wheel skipping is usually caused by dust or lint in the rotary encoder. Power off your mouse and use compressed air around the wheel gap to clear debris.

Quick Reference & Conversion Table

Button Name	Hardware Index	Event Name	Typical Primary Function
Left Button	Button 0	mousedown	Selection, dragging, and primary interaction
Middle Button	Button 1	auxclick	Tab opening and autoscroll navigation
Right Button	Button 2	contextmenu	Contextual action menus and secondary fire
Back Button	Button 3	auxclick	Browser history backwards navigation
Forward Button	Button 4	auxclick	Browser history forward navigation

⚠️ Common Pitfalls to Avoid

•Testing right-click outside the canvas where the default browser context menu blocks event monitoring.
•Assuming a mouse with stiff thumb buttons is broken when operating system software has mapped them to custom macros.
•Confusing double-click switch bouncing with intentional fast single clicking.

💡 Practical Real-World Uses

•Diagnosing double-clicking switch degradation on gaming mice (Omron/Huano switch wear).
•Testing scroll wheel skipping or reversed scrolling caused by dust in optical encoders.
•Verifying programmable side buttons on productivity and MMO mice.

Last reviewed & updated: 2026-11-07

Free & Open Access

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