Open any URL with origin as localhost:3000 #bookmarklet

open-localhost.js

javascript: void((function () {
  /* More bookmarklets at https://gist.github.com/iamandrewluca/61feacf07bc4f2f50e70f986c2e9b2d2 */
  /**
   * Add your own mappers, first found will be used
   * @type {{host: string, startsWith: string}[]}
   */
  const hostMapper = [
    { startsWith: 'https://example.org', host: 'localhost:3000' },
    { startsWith: 'https://example.org/admin', host: 'localhost:3001' },
  ];

  /** @type {string} */
  const href = window.location.href;
  const mapper = hostMapper.find(m => href.startsWith(m.startsWith));
  const a = document.createElement('a');
  a.href = href;
  a.protocol = 'http:';
  a.target = '_blank';
  a.host = mapper ? mapper.host : 'localhost:3000';
  window.document.body.appendChild(a);
  a.click();
  a.remove();
})());

What does this do?

@Doob123123 let's say you have a production website at https://my-website.com. And you also have locally started the development server on http://localhost:3000

if you go on https://my-website.com/some-url-here page and click the bookmarklet, will open http://localhost:3000/some-url-here