Link Attributes: rel=nofollow, sponsored and ugc

A link attribute is a value in the rel attribute of an <a> tag that tells Google something about your relationship with the page you are linking to. Three values matter for search: sponsored, ugc and nofollow.

A standard link needs no rel value at all. Google fetches and parses it without qualification.¹

What are the three link attributes?

rel=“sponsored”

Marks links that are advertisements, paid placements or any link that exists inside a commercial relationship. Affiliate links belong here. Google prefers sponsored for these links but still accepts nofollow, and treats the two the same for this purpose.¹²

<a rel="sponsored" href="https://example.com/product">Product name</a>

rel=“ugc”

Marks links inside user-generated content: blog comments, forum posts, profile fields, reviews. It signals that a site user placed the link rather than the site owner.

Google adds one piece of guidance most implementations miss: you may remove the attribute for contributors who have consistently made high-quality contributions over time.¹ The attribute describes provenance, not permanent distrust.

rel=“nofollow”

The fallback. Google’s wording is precise: use nofollow “when other values don’t apply, and you’d rather Google not associate your site with, or crawl the linked page from, your site”.¹

Introduced in 2005 to fight comment spam, it was the only option until 2019, which is why a great deal of existing markup uses it for cases that would now take sponsored or ugc.

Combining values

Values combine as a space-separated or comma-separated list. rel="ugc sponsored" and rel="ugc,nofollow" are both valid.¹ Combining nofollow with a newer value is a deliberate pattern: it stays readable to services that never adopted sponsored and ugc.²

Dofollow is not a real attribute. It is practitioner shorthand for a standard link carrying no rel restriction. You will never write it in markup.

Are link attributes directives or hints?

Hints. This is the most misunderstood point about them, and getting it wrong leads to reaching for the wrong tool.

When nofollow launched in 2005, Google discarded any link marked with it. That changed with the September 2019 announcement: all three attributes became “hints about which links to consider or exclude within Search”, with the change taking effect for ranking immediately and for crawling and indexing purposes on 1 March 2020.²

Google’s stated reason is that links carry information beyond endorsement. The announcement puts it directly: links help Google understand how the words in a link describe the content it points at, and looking at every link helps it “better understand unnatural linking patterns”. Discarding nofollowed links threw that away.²

Google’s current documentation states what follows from that: links carrying these attributes “will generally not be followed”, but the linked page “may be found through other means, such as sitemaps or links from other sites, and thus they may still be crawled”.¹

A link attribute is a statement about a link. It is not a control over what Google does with the page at the other end.

Which link attribute should you use?

Link type	Attribute
Advertisement, sponsorship, paid placement	sponsored
Affiliate link	sponsored
Blog comment, forum post, user profile	ugc
Link you do not want read as an endorsement	nofollow
Ordinary editorial link	No rel value

Google states there is no wrong attribute except in one direction: flagging a UGC or non-ad link as sponsored when it is not.² Under-specifying is tolerated. Over-claiming a commercial relationship is not.

Do you have to mark paid and affiliate links?

Yes, and this is the part with real consequences attached.

Google’s spam policies list “text advertisements or text links that don’t block ranking credit” as link spam, alongside advertorials and native advertising that pass ranking credit. The policy then names the remedy: buying and selling links is “a normal part of the economy of the web for advertising and sponsorship purposes”, and having such links does not violate the policies “as long as they are qualified with a rel="nofollow" or rel="sponsored" attribute value”.³

The attribute is what separates a legitimate paid placement from a link scheme. An unqualified paid link is a policy violation that can attract a manual action.

One clause catches sites publishing under contract: requiring a link as part of a Terms of Service or similar arrangement, without allowing the other party the choice of qualifying it, is itself listed as link spam.³

Do nofollow links pass any value?

Not as ranking credit in the way a standard link does. Google’s position is that these links do not carry the weight of a first-party endorsement, which is the purpose of the attribute.

Two qualifications stop that from being the full answer. Under the hint model Google reads the link rather than discarding it, so the surrounding information survives. And a nofollowed link on a high-traffic page still sends referral traffic, still builds brand recognition, and still exists as a citation a person or an AI system can follow. Those are not ranking signals, and they are not nothing.

The distinction also matters less for AI answers than for rankings: Semrush found nofollow links correlate with AI mentions almost identically to followed ones. The link building page covers that finding with the rest of the evidence on backlinks and AI search.

For how link equity actually moves between pages, see the PageRank and link equity page. This page covers the markup; that one covers the mechanism.

Common link attribute mistakes

Using nofollow to stop Google crawling your own pages. It cannot do that reliably, because Google may reach the page from a sitemap or an external link. For a page on your own site, Google’s documented instruction is the robots.txt disallow rule.¹

Using nofollow to keep a page out of the index. Wrong tool again. To prevent indexing, allow crawling and use the noindex robots rule, so Google can reach the page and see the directive.¹

Confusing link-level nofollow with the meta robots tag. <meta name="robots" content="nofollow"> applies to every link on a page. rel="nofollow" applies to one link. The nofollow value is the only one of the three available in both places.¹ They also carry different force, which is the part that causes the confusion: the meta robots version is a directive Google follows, while the link attribute is a hint.

Nofollowing internal links to shape PageRank. A legacy of PageRank sculpting, which had already stopped working before Google disclosed the change in June 2009. The mechanism matters: PageRank is divided across every link on a page, nofollowed ones included, so a nofollowed internal link consumes its share rather than passing it to the others.⁴ Internal links are yours to control by deciding whether to place them at all.

Retrofitting existing markup. Google is explicit that no change is required: existing nofollow links on ads continue to be supported, and switching to sponsored is a recommendation for convenience, not a correction.²

Frequently asked questions

Does an incoming nofollow link hurt my site?

No. The attribute sits on someone else’s page and describes their relationship with the link. It confers no penalty on you.

Should I nofollow outbound links to conserve authority?

No. Linking to good sources is ordinary editorial practice and carries no penalty. Reserve the attributes for links that genuinely are paid, user-placed or unendorsed.

Do other search engines treat these attributes the same way?

Not necessarily. The hint model and the 2019 attribute set are Google’s. Bing and other engines document their own handling, and AI retrieval systems publish no consistent rules for link attributes at all. Claims sourced from Google apply to Google.

Is rel="nofollow" still valid, or has sponsored replaced it?

Still valid. Google confirms existing nofollow markup continues to be supported, and that nofollow remains acceptable for flagging paid links, with sponsored preferred.¹²

Footnotes

1. Qualify your outbound links to Google — Google Search Central ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

2. Evolving “nofollow”, new ways to identify the nature of links — Google Search Central Blog ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

3. Spam policies for Google web search: Link spam — Google Search Central ↩ ↩²

4. PageRank sculpting — Matt Cutts, 15 June 2009. Cutts writes that “more than a year ago, Google changed how the PageRank flows”, so sculpting had stopped working before the post announced it. ↩