What is a referring URL? Definition and examples

A referring URL is the page a visitor was on right before they arrived at yours. If someone reads an industry blog and clicks a link to your pricing page, that blog post is the referring URL. Browsers pass it along automatically, and analytics tools use it to show where your traffic comes from.

How does a referring URL work?

When a visitor clicks a link, their browser requests the new page and includes a Referer header with the address of the page they came from. The misspelling is part of the HTTP standard itself. RFC 9110, the current HTTP specification, describes it as the URI of the resource "from which the target URI was obtained".

The website receiving the request can log that header. Google Analytics 4 stores it in the Page referrer dimension, which it describes as the user's previous URL, on your own domain or another.

Why is the referrer often incomplete or missing?

Browsers limit what they share to protect privacy:

Only the domain across sites. The default browser policy, strict-origin-when-cross-origin, sends the full URL within your own site but only the origin, such as https://example.com/, when the visitor moves to another secure site.
Nothing from HTTPS to HTTP. No referrer is sent from a secure page to an insecure one.
Nothing without a page. Typed addresses and bookmarks have no referrer.
Stripped on purpose. Links marked rel="noreferrer" don't send it, and some proxies and browser extensions remove it.

When the referrer is missing, analytics tools usually count the visit as direct traffic. That is why campaign links should carry UTM parameters (see tracking URL) instead of relying on the referrer.

Why do referring URLs matter for marketing?

GA4 groups visits from non-ad links on other sites and apps, such as blogs and news sites, into the Referral channel. Checking which referring sites send visitors tells you:

Which partners, directories, review sites and articles send real visitors.
Which of those visitors convert, so you know where to spend PR and partnership effort.
Where you are mentioned that you didn't know about.

For affiliate and partner programs, referral data is a useful check alongside the tracking links partners use.

Referring URLs and backlinks

A backlink is a link on another site that points to yours. When a visitor clicks it, the page holding that link shows up as the referring URL. SEO tools also count "referring domains": the number of different websites that link to you, whether or not anyone clicks.

How do you earn more referral traffic?

Publish things worth linking to, such as original data, templates and clear explanations.
Write for relevant sites through guest blogging where their readers are your buyers.
Get listed in directories, marketplaces and review sites your buyers use.
Work with partners on joint content, webinars and integrations pages.

Frequently asked questions

Why is the referring URL often only a domain, not the full page?

Modern browsers default to a referrer policy called strict-origin-when-cross-origin. When a visitor moves from one secure site to another, the browser sends only the origin, such as https://example.com/, and not the full path. Within the same site, the full URL is sent.

Why does some traffic show no referrer at all?

Browsers send no referrer when someone types the address, uses a bookmark, or moves from an HTTPS page to a plain HTTP page. Links marked rel="noreferrer" don't send it, and some proxies and browser extensions remove it. Analytics tools usually report this traffic as direct.

Is a referring URL the same as a backlink?

Not exactly. A backlink is a link from another site to yours. When someone clicks it, the page containing that link becomes the referring URL in your analytics. SEO tools also use "referring domains" to mean the number of different sites that link to you, whether or not anyone clicks.