Disable JavaScript Alert Boxes のソースコード

Disable JavaScript Alert Boxes

Blocks annoying page-load alert boxes during the first 5 seconds

2026/05/08のページです。最新版はこちら

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// ==UserScript==
// @name         Disable JavaScript Alert Boxes
// @namespace    RGlzYWJsZSBqYXZhc2NyaXB0IGFsZXJ0IGJveGVz
// @version      1.1
// @description  Blocks annoying page-load alert boxes during the first 5 seconds
// @author       smed79
// @license      GPLv3
// @icon         https://i25.servimg.com/u/f25/11/94/21/24/x10.jpg
// @include      *://*/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Inject directly into the Main World so we actually intercept the page's alerts
    const payload = `(function() {
        try {
            // Keep a private, hidden reference to the original alert
            const originalAlert = window.alert;

            // Override the page's alert function to do absolutely nothing
            window.alert = function() {};

            // Restore the original alert after 5 seconds
            setTimeout(() => {
                window.alert = originalAlert;
            }, 5000);
        } catch (e) {}
    })();`;

    // Create the script tag
    const script = document.createElement('script');
    script.textContent = payload;

    // Inject instantly at document-start before the website's spam scripts run
    if (document.documentElement) {
        document.documentElement.appendChild(script);
        script.remove(); // Clean up the tag so the website doesn't know we are there
    }
})();