Switch to HD version on page load™.
// ==UserScript==
// @name Gfycat/redgifs HD On
// @namespace https://github.com/kittenparry/
// @version 0.2
// @description Switch to HD version on page load™.
// @author kittenparry
// @include https://*.gfycat.com/*
// @include https://gfycat.com/*
// @include https://*.redgifs.com/*
// @include https://redgifs.com/*
// @grant none
// @license GPL-3.0-or-later
// ==/UserScript==
setTimeout(() => {
document.querySelector('span[class="settings-button"]').click();
}, 500);