It doesn’t help in-browser, but if you’re on macOS and using Finicky, you can add this to your `~/.finicky.js` under the `rewrite` rules:

    {
      match: ({ url }) => url.host === 'twitter.com',
      url: ({ url }) => {
        return { ...url, host: 'nitter.net' }
      },
    },

It goes along quite nicely with my `medium.com` to `scribe.rip` rule:

    {
      match: ({ url }) => url.host.endsWith('medium.com'),
      url: ({ url }) => {
        return { ...url, host: 'scribe.rip' }
      },
    },

(It should be possible to make it pick a random list from nitter mirrors.)

EDIT: Improved version that picks from random nitter redirectors (https://github.com/zedeus/nitter/wiki/Instances#third-party-...). It needs the following declared at the top of the `finicky.js` file:

    const NITTER_HOSTS = ['twiiit.com', 'twitit.gq']

    const nitterHost = () => NITTER_HOSTS[Math.floor(Math.random() * NITTER_HOSTS.length)]

Then the rewrite rule is:

    {
      match: ({ url }) => url.host === 'twitter.com',
      url: ({ url }) => {
        return { ...url, host: nitterHost() }
      },
    },

Privacy Redirect firefox browser plugin can do that: https://github.com/SimonBrazell/privacy-redirect

I use the Redirector[0] browser extension to do this, and it works great.

[0]: https://einaregilsson.com/redirector/