Link attributes describe why a hyperlink exists. For Google Search, the practical choice is straightforward: a normal editorial link does not need a special rel value; paid or advertising links should be qualified with rel=”sponsored” or rel=”nofollow”, with sponsored preferred; user-generated links can use rel=”ugc”; and rel=”nofollow” is appropriate when the other values do not apply and you would rather Google did not associate your site with, or crawl, the destination from that link.
The difficult part is not writing the HTML. It is classifying the relationship correctly. A link can be useful to readers and still be commercial. A link can be added by a user and also be sponsored. And an authoritative source cited by an editor normally does not become more trustworthy because it has been nofollowed.
Choose the Attribute by Asking Why the Link Exists
Start with the reason for the link rather than the SEO outcome you hope to control. This keeps the decision tied to the real relationship between the publisher and the destination.
Was there payment, commission or another commercial benefit?
For advertisements, paid placements, sponsorships and affiliate links, Google recommends rel=”sponsored”. Google also states that rel=”nofollow” remains acceptable for paid links, although sponsored is preferred because it describes the relationship more precisely.
This distinction matters for guest contributions and partnerships as well. A guest article is not automatically sponsored, but payment, free products, affiliate arrangements or another incentive can change how its links should be qualified. The separate guide to guest posting for SEO covers that broader editorial context.
Was the link added by a user?
Google recommends rel=”ugc” for links in user-generated content such as comments and forum posts. A site can choose to treat established, trustworthy contributors differently over time, so UGC is not a permanent label that must remain on every user link regardless of moderation or contributor history.
If the user-generated link is also paid, both relationships can be expressed in the same attribute, for example rel=”ugc sponsored”.
If neither applies, does the link need qualification at all?
Usually, no. Google says regular links that it can fetch and parse without qualification do not need a rel attribute. That is the appropriate default for a useful editorial citation to a source you are willing to associate with the page.
Use rel=”nofollow” when sponsored and UGC do not describe the relationship and you would rather Google did not associate your site with, or crawl, that destination from your link. For a broader comparison between ordinary links and nofollow links, see dofollow vs nofollow.
What the HTML Should Look Like
The rel value belongs inside the opening <a> tag. A normal editorial link needs no special relationship value:
<a href="https://example.com">Editorial source</a>
<a href="https://example.com" rel="sponsored">Paid partner</a>
<a href="https://example.com" rel="ugc">User-submitted link</a>
<a href="https://example.com" rel="nofollow">Unendorsed reference</a>
<a href="https://example.com" rel="ugc sponsored">Paid link in user-generated content</a>
Google allows multiple relationship values on the same link. Using spaces between values is simple and easy to inspect in source code. The order of the values is not the important part; the relationship they describe is.
These values are technical signals for search systems. They are not a visible sponsorship notice for readers. If a commercial relationship also requires a reader-facing disclosure under your advertising rules, contract or applicable law, the rel attribute does not replace that disclosure.
Common edge cases
- Affiliate review: the commission creates a commercial relationship, so sponsored is the clearest value.
- Unpaid guest contribution: the fact that another person wrote the article does not by itself make every outbound link sponsored. Review how each link was selected and whether any compensation influenced it.
- Paid profile link in a community: both user-generated and commercial conditions apply, so rel=”ugc sponsored” can describe both.
- Critical or cautionary reference: if you need to cite a page but do not want Google to associate your site with it, nofollow may be appropriate.
- Ordinary editorial source: no qualifier is normally needed simply because the destination is external.
Do these attributes completely switch ranking signals off?
No. Google has treated sponsored, ugc and nofollow as hints for ranking purposes since the change announced in 2019. Its current outbound-link documentation also says links carrying these values will generally not be followed. That is a reason to classify links accurately, not a reason to use the attributes as a mechanical PageRank-control system.
Three Implementation Mistakes Worth Fixing
Most errors come from using one rule everywhere instead of checking the relationship each time.
1. Nofollowing every external citation
A blanket nofollow rule is not required by Google. If an editor cites Google Search Central, an original study or another source because it supports the article, a normal link can accurately represent that editorial relationship. Applying nofollow to every external source makes the markup less descriptive, not more cautious.
2. Treating UGC as a substitute for sponsored
UGC describes where or by whom a link was added. Sponsored describes a commercial relationship. Those facts can coexist. A paid link inside a community profile, for example, can use both values.
3. Using nofollow to manage your own indexation
Nofollow is a poor substitute for page-level crawl and index controls. Google advises using robots.txt when you need to prevent crawling of an internal URL and a noindex rule when you need to prevent indexing. Ordinary internal navigation should not be nofollowed simply to sculpt authority or hide pages from Search.
Attribute choice also does not fix misleading anchor text. The destination still needs to match what the clickable wording promises, which is why clear anchor text should be reviewed separately from link qualification.
Build Link Qualification Into the Publishing Workflow
On a small site, editors can usually make the decision link by link. At scale, inconsistency becomes the bigger risk. Affiliate modules, sponsored-post templates, comment systems and contributor profiles should apply the expected values automatically where the relationship is known, with editorial review for exceptions.
A practical review can be kept short:
- Confirm whether compensation or another commercial benefit influenced the link.
- Check whether the publisher or a user added it.
- Leave genuine editorial citations as normal links unless there is a specific reason to qualify them.
- Combine values when more than one relationship genuinely applies.
- Inspect the rendered HTML after publishing, especially when a CMS or plugin modifies link attributes automatically.
The useful rule is not ‘nofollow external links’. It is ‘describe the relationship that actually exists’. That produces cleaner markup and gives editors a defensible reason for each attribute choice.
