Link attributes are values added to a link's rel attribute that tell search engines about the relationship between your page and the page you're linking to. The main ones for SEO are rel="sponsored" for paid or advertising links, rel="ugc" for links in user-generated content, and rel="nofollow" for other links you don't want to vouch for.
For businesses, link attributes are about honesty and risk. Marking paid and user-submitted links correctly keeps you within Google's spam policies, protects your site's reputation, and shows search engines which links you actually endorse.
What are link attributes?
An HTML link can carry a rel attribute that describes how the current page relates to the linked page. For search, Google recognizes three main values, described in its guide to qualifying your outbound links:
- rel="sponsored": Google says to mark links that are advertisements or paid placements with the sponsored value.
- rel="ugc": Google recommends marking user-generated content links, such as comments and forum posts, with the ugc value.
- rel="nofollow": Google says to 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.
Before 2019, nofollow was the only option. On September 10, 2019, Google announced sponsored and ugc in a post titled "Evolving nofollow: new ways to identify the nature of links".
Why link attributes matter
They keep paid links within the rules. Google's spam policies list buying or selling links for ranking purposes as link spam, including advertorials with links that pass ranking credit. The same policies say buying and selling links for advertising is fine if the links are qualified with rel="nofollow" or rel="sponsored".
They protect sites that host user content. Comment sections, forums and review pages attract spam links. Marking those links as ugc tells Google you don't necessarily vouch for them. See user-generated content for more on managing these sections.
They clarify your link profile. Influencer posts, affiliate links, sponsorships and partnerships all involve some value exchange. Labeling them correctly reduces the chance that they look like a link building scheme.
They don't erase visibility. A sponsored or nofollowed mention on the right site can still send referral traffic and build brand awareness. AI assistants that read web pages see the brand name in the text regardless of the link's attribute.
How link attributes work
The markup
The attribute sits inside the link tag, like <a href="https://example.com" rel="sponsored">. Google says you can combine values in a space- or comma-separated list, such as rel="ugc nofollow".
Hints, not commands
When Google introduced the new values, it also changed how it treats them. All three became hints that Google takes into account when deciding how to treat a link. For ranking, that applied straight away. As Search Engine Journal reported, Google said that for crawling and indexing purposes, nofollow would become a hint as of March 1, 2020. Google's documentation notes that linked pages may still be crawled if Google finds them another way, such as through sitemaps or links from other sites.
Existing nofollow links
Google said there was absolutely no need to change any nofollow links sites already had. Its documentation still says nofollow is an acceptable way to flag paid links, though sponsored is preferred.
Rewarding trusted contributors
Google's guidance suggests that site owners might remove the ugc attribute from links added by members who have consistently made high-quality contributions over time. That lets you reward trusted community members without opening the door to spam.
How to use link attributes correctly
- Mark every paid link as sponsored. This includes sponsored posts, paid directory listings, affiliate links and links given in exchange for free products.
- Mark user-submitted links as ugc. Set your CMS, forum or comment system to add it automatically.
- Use nofollow for links you don't want to endorse when the other values don't fit.
- Leave normal editorial links alone. Links you choose to give because they help readers don't need an attribute.
- Don't nofollow your own internal links. If you need to stop Google fetching a page on your own site, Google's guidance points to a robots.txt disallow rule instead. Otherwise, use internal links freely.
- Ask for it in sponsorship agreements. When you pay for placements, make sure the publisher qualifies the links.
Common mistakes and misconceptions
"Sponsored links are bad for SEO." Correctly labeled paid links are allowed. The problem is paid links that pass ranking credit without being qualified.
"Nofollow links are worthless." Google treats them as hints, and they can still drive traffic and brand exposure. Many natural link profiles include them.
"Using the wrong attribute will get you penalized." Google's 2019 announcement said there's no wrong attribute except in the case of sponsored links. Mixing up ugc and nofollow isn't a problem. Failing to flag paid links is.
"Nofollow stops a page from being indexed." It doesn't. To keep a page out of the index, use a noindex tag on that page.
Sponsored vs. UGC vs. nofollow
Use sponsored when money, products or another form of payment was involved. Use ugc when the link was added by users rather than your editorial team. Use nofollow as the general-purpose option when you don't want to vouch for a link and the other two don't apply.
How Butter approaches link attributes
Link attributes aren't a service on their own at Butter, but they show up throughout our work. When we review a site, we check that paid, affiliate and user-generated links are qualified correctly, and that internal links aren't being nofollowed by mistake. Those recommendations show up in our monthly on-page and off-page reports.
In our link building work, we look at relevance and audience first and the attribute second, because a mention on the right site still builds visibility for both search and AI answers. We don't buy links from networks. You can see how this fits into a broader program on our SEO service page.
Frequently asked questions
What is the difference between rel="sponsored" and rel="nofollow"?
Sponsored marks paid or advertising links specifically. Nofollow is the general option for links you don't want to endorse. Google accepts either for paid links but prefers sponsored.
Do I need to change old nofollow links to sponsored?
No. Google said there's no need to change nofollow links you already have. Using sponsored for new paid links is the preferred approach.
Can I use more than one link attribute?
Yes. Google says you can combine values in a space- or comma-separated list, such as rel="ugc nofollow", when more than one description applies.
Do sponsored and UGC links help rankings?
Google treats these attributes as hints, so it decides how much weight, if any, to give the link. Their main value is usually traffic, brand exposure and staying within Google's policies.