What is Referrer?

The referrer (or HTTP referer) is the URL of the page that linked to the current page. When a user clicks a link on another website, their browser sends the originating URL in the Referer header, allowing analytics tools to track where traffic comes from.

Referrer data helps you understand your traffic sources: which websites link to you, which social platforms drive visits, and which search engines send users your way. This information is essential for evaluating marketing channels and partnerships.

Note that referrer data isn't always available. Users arriving via bookmarks, direct URL entry, or some privacy-focused browsers will show as "direct" traffic. HTTPS-to-HTTP transitions also strip referrer data.