How to fix ERR_CONNECTION_TIMED_OUT (Windows, Mac OS, Android, iOS) (Mac OS)

Via the "hosts" file, you may add URLs of webpages you want to block, which will automatically be blocked in every single browser installed in your computer. Also, there are viruses and pieces of software that can modify the "hosts" file just to prevent you from downloading an antivirus software which can locate and remove the virus, or from visiting a particular website.
 
As a solution to the "This website can't be accessed ERR_CONNECTION_TIMED_OUT" error, you need to open and modify the hosts file. To modify the "hosts" file:

1.  Open the Terminal.app by going into Applications -> Utilities -> Terminal.
   
   
2. Type the following line: sudo nano /private/etc/hosts (type your username and password when asked)
   
   
3. If you notice a URL of a websites you visit, or websites of antivirus software, delete them and press and hold Control + O to save the changes and Control + X to exit
   
   
4. Flush the DNS cache by entering the following line (depending on your OS version):
   
   
   • dscacheutil -flushcache - Mac OS X Snow Leopard (v10.6 through v10.6.8)
     
     
   • sudo killall -HUP mDNSResponder - Mac OS X Mavericks, Mountain Lion, and Lion (v10.9.5 and earlier)
     
     
   • sudo discoveryutil mdnsflushcache - Mac OS X Yosemite and later (v10.10 through v10.10.3)
     
     
   • sudo killall -HUP mDNSResponder - Mac OS X Yosemite and later (v10.10.4 or later)