Tampermonkey

remove-utm.js

// ==UserScript==
// @name         Remove utm_
// @namespace    http://mysticatea.jp/
// @version      1.0.0
// @description  Remove utm_* from URL parameters.
// @author       Toru Nagashima
// @match        *://*/*?*utm_*
// @grant        none
// ==/UserScript==

const url = new URL(location.href)

let removed = false
for (const key of url.searchParams.keys()) {
    if (key.startsWith("utm_")) {
        url.searchParams.delete(key)
        removed = true
    }
}

if (removed) {
    history.replaceState(null, null, url)
}