Tampermonkey Script

// ==UserScript==
// @name         Taobao/TMall Link Shrinker
// @namespace    https://jest.one/
// @version      0.1
// @description  Shrink Taobao/TMall links
// @author       You
// @match        *://*.taobao.com/item.htm*
// @match        *://*.tmall.com/item.htm*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    if (getParamsCount() > 1) {
        redirectToSimpleUrl();
    }

    // TMall would replace your simple URL with a longer one some time after the page is loaded; this reverts it
    let intervalID = window.setInterval(() => {
        if (getParamsCount() > 1) {
            replaceWithSimpleUrl();
        }
    }, 500);

    ///////////////////////////

    function getParamsCount() {
        let urlParams = new URLSearchParams(window.location.search);  // e.g. ?id=627682809552&skuId=4629184475544
        let paramsCount = [...urlParams.entries()].length;
        console.log(paramsCount);
        return paramsCount;
    }

    function getItemID() {
        let urlParams = new URLSearchParams(window.location.search);  // e.g. ?id=627682809552&skuId=4629184475544
        let itemID = urlParams.get("id"); // e.g. 627682809552
        return itemID;
    }

    function buildSimpleUrl() {
        let origin = window.location.origin; // e.g.  https://detail.tmall.com
        let newUrl = `${origin}/item.htm?id=${getItemID()}`;
        return newUrl;
    }

    function redirectToSimpleUrl() {
        let newUrl = buildSimpleUrl();
        console.log(`Redirecting to ${newUrl}`);
        window.location.href = newUrl;
    }

    function replaceWithSimpleUrl() {
        let newUrl = buildSimpleUrl();
        console.log(`Replacing history state to ${newUrl}`);
        window.history.replaceState(null, null, newUrl);
    }

})();