Mouse Tracker

Ultra-lean Mouse cursor overlay with pointer tracking + robust DOM-safe injection

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

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You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

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// ==UserScript==
// @name         Mouse Tracker
// @namespace    ultralean.universal.mouse.tracker
// @version      1.6.0
// @description  Ultra-lean Mouse cursor overlay with pointer tracking + robust DOM-safe injection
// @author       Michael Stutesman
// @license      MIT
// @match        *://*/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(() => {
    'use strict';

    // --------------------------------------------------
    // Singleton Guard (hard safe)
    // --------------------------------------------------
    if (globalThis.__OBS_MOUSE_TRACKER__) return;
    globalThis.__OBS_MOUSE_TRACKER__ = true;

    // --------------------------------------------------
    // Config
    // --------------------------------------------------
    const SIZE = 18;
    const COLOR = 'rgba(204,204,204,0.9)';
    const BORDER = 2;
    const BORDER_COLOR = 'rgba(255,255,255,0.9)';
    const SHADOW = '0 0 10px rgba(0,200,255,0.8)';
    const Z = 2147483647;
    const HIDE_DELAY = 80;

    // --------------------------------------------------
    // State
    // --------------------------------------------------
    let hideTimeout = 0;
    let rafId = 0;
    let lastX = 0;
    let lastY = 0;

    // --------------------------------------------------
    // Elements (declared early, mounted safely later)
    // --------------------------------------------------
    const container = document.createElement('div');
    const tracker = document.createElement('div');

    Object.assign(container.style, {
        position: 'fixed',
        inset: '0',
        pointerEvents: 'none',
        zIndex: Z,
        contain: 'strict',
        transform: 'translate3d(0,0,0)',
    });

    Object.assign(tracker.style, {
        width: `${SIZE}px`,
        height: `${SIZE}px`,
        borderRadius: '50%',
        background: COLOR,
        border: `${BORDER}px solid ${BORDER_COLOR}`,
        boxShadow: SHADOW,
        pointerEvents: 'none',
        transform: 'translate3d(-50%,-50%,0)',
        opacity: '0',
        transition: 'opacity 0.1s linear',
        willChange: 'transform, opacity'
    });

    container.appendChild(tracker);

    // --------------------------------------------------
    // Render (rAF optimized)
    // --------------------------------------------------
    const render = () => {
        rafId = 0;

        tracker.style.transform =
            `translate3d(${lastX}px,${lastY}px,0) translate(-50%,-50%)`;

        tracker.style.opacity = '1';

        clearTimeout(hideTimeout);
        hideTimeout = setTimeout(() => {
            tracker.style.opacity = '0';
        }, HIDE_DELAY);
    };

    // --------------------------------------------------
    // Input (fast path — pointer events)
    // --------------------------------------------------
    const onMove = (e) => {
        lastX = e.clientX;
        lastY = e.clientY;

        if (!rafId) {
            rafId = requestAnimationFrame(render);
        }
    };

    const onLeave = () => {
        tracker.style.opacity = '0';
    };

    // --------------------------------------------------
    // Safe mount (DOM-ready tolerant)
    // --------------------------------------------------
    const mount = () => {
        const parent = document.body || document.documentElement;
        if (!parent) return;

        parent.appendChild(container);

        // Attach input AFTER mount (prevents edge timing bugs)
        window.addEventListener('pointermove', onMove, { passive: true });
        document.addEventListener('pointerleave', onLeave);
    };

    // --------------------------------------------------
    // Init guard (handles document-start safely)
    // --------------------------------------------------
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', mount);
    } else {
        mount();
    }

})();