Unblock all blocked Twitter accounts at once

If you have blocked hundreds of accounts, unblocking them one by one takes a lot of time. But there is a quick and easy way to unblock them all at once. You don’t need to give any app write permissions to your account for it to work.

Short version:
Got to the blocked accounts setting page, scroll to the bottom and run
$('.user-actions-follow-button').click()
in the browser console.

Long version:

1. Go to the settings

On this page you see all accounts your are blocking at the moment:
https://twitter.com/settings/blocked

2. Open the Developer Tools

Quickest way: Press F12 on Windows/Linux or Command+Option+I on MacOS. Tested on Chrome and Firefox.
You can go through the menu as well. Firefox: Extras -> Web Developers. Chrome: Other Tools -> Developer Tools.

You should now see a new area in your browser. Either on the right side or on the bottom of the window.