How to Track Google Analytics Referral Path

Question

How google will track Referral Path from site1 to site2 without Google Analytics URL Builder (UTM)?

Can any one answer for my question?

Answer 1

You can use plain javascript document.referrer

if ('referrer' in document)
            {
                if (document.referrer != '')
                    ref = encodeURIComponent(document.referrer);

            }