"noreferrer" attribute

This means the linked-to site cannot see where the traffic came from in Analytics, and it also disables the browser's window.opener access, preventing the new page from manipulating the original tab.

It's commonly paired with noopener (as rel="noopener noreferrer") on external links that open in a new tab, both as a privacy measure and a security safeguard against reverse tabnabbing.

What it is

noreferrer is a value for the rel attribute on a link:

<a href="https://example.com" target="_blank" rel="noreferrer">Visit site</a>

It does two things:

1. Strips the referrer. When someone clicks the link, the browser does not send the Referer HTTP header (and hides document.referrer) to the destination. The destination site has no idea the visitor came from your page.
2. Implies noopener. noreferrer also severs the window.opener reference, so you get the tabnabbing protection of noopener for free.

The first behaviour — hiding the referrer — is what makes noreferrer meaningfully different from noopener, and it's where the SEO consequences live.

SEO impact

Like noopener, noreferrer does not affect crawling, indexing, or link equity. It is not a nofollow equivalent. A noreferrer link still passes ranking signals to its destination the same way a normal link does. It should not be confused with link-attribute values that do control equity (nofollow, sponsored, ugc).

The real impact of noreferrer is on referral attribution and Analytics, in two directions:

When you put noreferrer on your outbound links

The sites you link to lose the ability to see you as a traffic source. In their Google Analytics, GA4, or server logs, your referral traffic shows up as direct / unknown instead of being credited to your domain.

Why this matters for SEO and partnerships: - You become invisible as a referrer. If you're sending valuable traffic to a partner, client, or affiliate, they can't see it came from you. - Affiliate and partner tracking can break. Some programs rely on the referrer to attribute clicks and conversions. noreferrer can cause those clicks to go uncredited.

When other sites put noreferrer on links to you

This is the flip side, and it's a common, frustrating Analytics gotcha. If a site links to you with rel="noreferrer", the traffic they send lands in your reports as direct traffic rather than as a referral from their domain. As a result:

• Your referral numbers understate where visitors actually come from.
• Real backlinks driving real clicks can be hidden in your Analytics — appearing as unexplained direct traffic.

Note: this is purely an Analytics/measurement effect. The backlink itself still exists, can still be crawled, and can still pass ranking signals.

noreferrer hides the traffic source in reporting, not the link from search engines. While search engines themselves are unaffected, this disconnect makes accurate reporting impossible and creates challenges in evaluating the performance of different marketing channels.

Practical implementation

• For most internal and editorial outbound links, prefer noopener alone (or rely on the browser default) so you don't blind partners' Analytics unnecessarily.
• Use noreferrer deliberately, when you actually want to hide that traffic came from your page — e.g. linking out from sensitive pages, or when you don't want to leak internal URLs in the referrer string.
• Be aware of incoming noreferrer when diagnosing traffic. A spike in "direct" traffic with no obvious cause is often referral traffic stripped by noreferrer (or by HTTPS-to-HTTP referrer loss, or app/email clients).
• Don't treat it as a link-equity management tool. It isn't one.

In summary

noreferrer is a privacy/security attribute that hides the traffic source and also includes noopener protection. It's neutral for rankings and link equity, but it has a genuine downstream effect on how referral traffic is attributed — both for the sites you link to and the sites that link to you.

noreferrer serves a very specific purpose. If you're not linking from sensitive pages whose URLs you'd rather not leak, it's unnecessary, and the majority of websites do not need it.