Greasy Fork is available in English.

Imgur Mirror

Switches all imgur links to the mirror site http://kageurufu.net/imgur

// ==UserScript==
// @name         Imgur Mirror
// @namespace    https://greasyfork.org/users/649
// @version      1.1.6
// @description  Switches all imgur links to the mirror site http://kageurufu.net/imgur
// @author       Adrien Pyke
// @include      http*
// @require      https://gitcdn.link/repo/fuzetsu/userscripts/b38eabf72c20fa3cf7da84ecd2cefe0d4a2116be/wait-for-elements/wait-for-elements.js
// @grant        none
// ==/UserScript==

(() => {
  'use strict';

  const regex = /imgur\.com\/(?!a\/|gallery\/)(?:r\/[a-z0-9_]+\/)?([a-z0-9]+)(\.+[a-z0-9]+)?/iu;
  const extensions = ['.jpg', '.jpeg', '.png', '.gif', '.gifv', '.webm', '.mp4'];

  const getNewLink = function (imgurLink, useGif) {
    const match = imgurLink.match(regex);
    if (match) {
      const file = match[1];
      let extension = match[2].toLowerCase();
      if (!extension || !extensions.includes(extension)) {
        extension = '.png';
      } else if (extension === '.gifv' || extension === '.gif' || extension === '.webm') {
        extension = '.mp4';
      }
      if (useGif && extension === '.mp4') {
        extension = '.gif';
      }
      return `http://kageurufu.net/imgur/?${file + extension}`;
    } else {
      return null;
    }
  };

  waitForElems({
    sel: 'img,a',
    onmatch(node) {
      const isImg = node.nodeName === 'IMG';
      const prop = isImg ? 'src' : 'href';
      const newLink = getNewLink(node[prop], isImg);
      if (newLink) {
        node[prop] = newLink;
        if (node.dataset.hrefUrl) {
          node.dataset.hrefUrl = newLink;
        }
        if (node.dataset.outboundUrl) {
          node.dataset.outboundUrl = newLink;
        }
      }
    }
  });
})();