JQuery AJAX To Node Server Throws Net::ERR_CONNECTION_REFUSED

I have disabled my firewall (ufw on Ubuntu 15.04 server). This seems to be the most common cause of this problem. Additionally some people have problems using AJAX, so I tried with

Solution 1:

data: JSON.stringify(testdata),

That's probably your problem. You need to serialize your json object. And you need to set the .ajax call to type of POST in options otherwise it will default to a get.