Facebook Dark Theme Sync

Switch Facebook's theme to match the system

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Facebook Dark Theme Sync
// @namespace    http://tampermonkey.net/
// @version      0.3
// @description  Switch Facebook's theme to match the system
// @author       You
// @match        https://www.facebook.com/*
// @require      http://code.jquery.com/jquery-3.4.1.min.js
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    $( document ).ready(function() {
        let systemDarkEnabled = (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches)
        let isDarkEnabled = $('body').html().indexOf('["CometDarkModeSetting",[],{"initialSetting":"ENABLED"}') != -1;
        console.log("systemDarkEnabled " + systemDarkEnabled + " isDarkEnabled " + isDarkEnabled);
        setTimeout(function() {
            //Check if themes are not in sync
            if(systemDarkEnabled != isDarkEnabled){
                if(systemDarkEnabled){
                    document.querySelector('html').classList.add('__fb-dark-mode');
                }else{
                    document.querySelector('html').classList.remove('__fb-dark-mode');
                }
            }
        }, 1000);
    });
})();