Rel Attributes Explained: nofollow, sponsored, ugc

Three small words sit inside the rel attribute of an HTML link, and they quietly shape how Google interprets every outbound connection on your website. rel="nofollow" tells search engines that you don't want to pass ranking credit through a link — you're linking somewhere, but you're not necessarily endorsing it. rel="sponsored" flags a link as paid or part of an advertisement, sponsorship deal, or any arrangement where money or goods changed hands. And rel="ugc" marks links that appear in user-generated content — comment sections, forum posts, community profiles, that kind of thing. Each one serves a different purpose, and while they overlap in some ways, Google treats them as distinct signals about the relationship between your page and whatever you're linking to.

Key Takeaways

• What Does rel="nofollow" Actually Do?
• What About rel="sponsored"?
• And Then There's rel="ugc"
• Can You Combine Them?
• What Happens If You Use the Wrong One?
• What Google Has Actually Said

I think the confusion around these three attributes is wildly disproportionate to how simple they actually are. But I also understand why people get tangled up. For over a decade, we only had nofollow. It was the catch-all. Paid link? Nofollow it. Comment spam? Nofollow. Don't trust the destination? Nofollow. Then in September 2019, Google introduced sponsored and ugc as additional options, and suddenly people weren't sure if they were supposed to replace all their existing nofollow tags or what. So let's just walk through this carefully.

What Does rel="nofollow" Actually Do?

When Google first introduced the nofollow attribute back in 2005, the intent was straightforward: give webmasters a way to link to a page without passing PageRank. The problem at the time was blog comment spam. Automated bots were flooding comment sections with links to shady sites, and because those links passed ranking value by default, spammers had a real incentive to keep doing it. Nofollow was the solution. Slap rel="nofollow" on comment links, and suddenly those spam links lost their SEO value.

Here's the HTML. Pretty basic:

<a href="https://example.com" rel="nofollow">Example Site</a>

For years, Google treated nofollow as a directive. If a link had nofollow, Google would not follow it, would not crawl the destination through that link, and would not pass any ranking credit. It was absolute. A wall. But that changed in 2019 when Google announced they would begin treating nofollow as a hint. That's a meaningful shift. Google now reserves the right to crawl, index, and even pass some value through nofollow links if their algorithms determine it's appropriate. They haven't been super specific about when or why they'd override the hint, but the implication is clear: nofollow no longer guarantees that a link is invisible to Google's ranking calculations.

Does that mean nofollow is useless now? No. It still signals your intent. You're telling Google, "I'm not vouching for this." And in most cases, Google probably still honors that signal. But it's no longer a guarantee, and that's worth knowing. You might also find How Affiliate Links Affect Your SEO Rankings useful here.

What About rel="sponsored"?

This one is specifically for paid links. Affiliate links. Sponsored content. Any link where there's a financial relationship between you and the site you're linking to. If a company paid you to write a blog post and include a link to their product — that's a sponsored link. If you're earning a commission through an affiliate program every time someone clicks your link and buys something — sponsored. If you traded services, received free products for review, or have any other material connection — sponsored.

<a href="https://product-site.com" rel="sponsored">Check out this product</a>

Q: Do I have to use rel="sponsored" for affiliate links, or is nofollow fine?

Google has said that nofollow is still acceptable for marking paid links. You won't get penalized for using nofollow instead of sponsored on an affiliate link. However, Google prefers the more specific attribute because it gives them cleaner data. Think of it this way: nofollow says "I don't endorse this link" but doesn't explain why. Sponsored says "this is a paid relationship." The second one is more informative. If Google is trying to understand patterns around commercial link placement, the sponsored attribute helps them do that more accurately.

Q: What if I don't mark my paid links at all?

This is where it gets serious. Google's link spam policies are explicit: links that are part of "link schemes" — which includes buying or selling links that pass PageRank — violate their guidelines. If you're placing paid links without any rel attribute marking them as such, you're passing ranking credit through commercial relationships, and that's exactly what Google penalizes. Manual actions for "unnatural outbound links" are real, and they can tank your site's rankings. I've seen it happen. The site publishes a bunch of sponsored posts with clean dofollow links, Google catches on, and suddenly every page on the domain drops twenty positions overnight.

Just mark your paid links. It's not hard.

And Then There's rel="ugc"

UGC stands for user-generated content. If you run a site where users can post comments, forum replies, profile descriptions, wiki edits, or any other content that you didn't write or fully control, the links within that content should ideally be marked with rel="ugc".

<a href="https://user-submitted-link.com" rel="ugc">My website</a>

The reasoning is similar to why nofollow was originally created. User-generated content is a magnet for spam. People will dump links to their sites in comment sections, forum signatures, profile bios — anywhere they can get a free backlink. By marking those links with rel="ugc", you're telling Google, "Hey, a user put this here, not us. We didn't choose to endorse this destination." It protects you from being held responsible for whatever your users are linking to.

Q: My forum has been using nofollow on all user links for years. Do I need to change them all to ugc?

No. Google was very clear about this when they launched the new attributes. Existing nofollow usage doesn't need to be updated. If your platform already applies nofollow to user-generated links, that's perfectly fine and you can leave it as is. The ugc attribute is an option, not a requirement. It gives Google more granular information, which they appreciate, but failing to switch from nofollow to ugc won't cause any problems for your site. For a deeper look at this topic, see our guide on White Hat vs Black Hat Link Building: What You Must Know.

That said, if you're building a new platform or updating your CMS templates anyway, using ugc for user-submitted links is the cleaner approach going forward. It's a best practice, not a mandate.

Can You Combine Them?

Yes. You can absolutely use multiple rel values on a single link. This is something people miss. The rel attribute accepts a space-separated list of values, so you can do things like:

<a href="https://example.com" rel="nofollow sponsored">Paid Link</a>

<a href="https://user-link.com" rel="nofollow ugc">User's Site</a>

The first example marks a link as both nofollow and sponsored. The second marks it as both nofollow and user-generated. Both are valid. In fact, Google's own documentation shows combined usage as acceptable. If you want to be extra explicit — if you want to say "this is a paid link AND I don't want to pass credit" — combining nofollow with sponsored covers both bases. Some CMS platforms do this automatically. WordPress, for example, adds rel="nofollow ugc" to comment links by default in newer versions.

You can even combine all three if you somehow had a paid link submitted by a user that you also didn't want to endorse. I'm not sure when that exact scenario comes up, but technically, rel="nofollow sponsored ugc" is valid HTML.

What Happens If You Use the Wrong One?

Honestly? Probably nothing catastrophic. And I want to be careful here because I see people panic about this, and the panic is usually worse than the actual risk.

If you mark a paid link as ugc instead of sponsored — it's not ideal, but you're still signaling to Google that the link shouldn't be treated as a normal editorial endorsement. You're unlikely to face a manual penalty for that kind of misattribution. Google's systems are sophisticated enough to understand that the link is flagged in some way.

If you use nofollow where sponsored would be more appropriate — that's fine. Google said so directly. Nofollow was the standard for paid links for 14 years before the sponsored attribute even existed. The entire web is full of paid links marked with nofollow, and Google isn't going to suddenly penalize everyone for not retroactively switching to the newer attribute. Related reading: 301 vs 302 Redirects: Impact on Link Equity.

Where you can get into real trouble is the opposite scenario: not marking a paid link with anything at all. A clean, bare <a href> tag on a link you were paid to place — that's the problem case. That's what Google considers a link scheme violation. The distinction isn't really between nofollow, sponsored, and ugc. It's between "marked" and "unmarked."

There's a more subtle issue, though. If you mark regular editorial links as nofollow when they don't need to be, you're potentially withholding ranking credit from pages that deserve it. I've seen sites where an overzealous developer added nofollow to every external link on the site, including genuine editorial references to high-quality sources. That doesn't help anyone. It doesn't help the sites you're linking to, and it might reduce your own perceived trustworthiness in Google's eyes. Sites that link out generously to good sources tend to be seen as higher quality themselves — there's some evidence that outbound link quality correlates with rankings, though the data isn't conclusive.

What Google Has Actually Said

Let me pull together some of the key statements Google has made about these attributes, because I think going back to the source helps cut through the noise.

In September 2019, Google published a blog post titled "Evolving 'nofollow' — new ways to identify the nature of links." In it, they explained that nofollow was being joined by sponsored and ugc, and that all three attributes would be treated as hints for ranking purposes starting March 1, 2020. For crawling and indexing purposes, the hint model took effect immediately.

Gary Illyes from Google said on Twitter (well, X now) that the change was partly motivated by the fact that nofollow links contain valuable signals that Google was completely ignoring under the old directive model. By treating them as hints, Google could selectively choose to use nofollow link data when it was genuinely useful — like when a nofollow link from the New York Times points to a small site that deserves to be discovered.

John Mueller, another Google spokesperson, has reiterated multiple times that switching from nofollow to sponsored or ugc is not required. He's described it as a way to "help Google better understand the nature of links" but has consistently downplayed the urgency. "If you have nofollow in place, that's fine," he's said in various Webmaster Hangouts.

Google's Search Central documentation currently states: "Use the sponsored attribute to identify links on your site that were created as part of advertisements, sponsorships, or other compensation agreements." For ugc: "UGC is recommended for links within user-generated content, such as comments and forum posts." And for nofollow: "Use the nofollow attribute for cases where you want to link to a page but don't want to imply any type of endorsement, including passing along ranking credit to another page." If this is new to you, Canonical Tags and Their Effect on Links breaks it down step by step.

Pretty straightforward. Yet I still see SEO forums with 200-reply threads debating whether using nofollow instead of sponsored on an affiliate link will get your site penalized. It won't. I promise. Or — well, I'm about 99% confident it won't. Nobody can promise anything about Google's algorithm with absolute certainty. But based on everything Google has communicated, using nofollow for paid links remains acceptable.

Practical Implementation

Let me give you a quick decision framework, because sometimes a simple checklist is worth more than pages of explanation.

Is the link paid, sponsored, or part of an affiliate arrangement? Use rel="sponsored" or rel="nofollow". Either works. Sponsored is preferred by Google but nofollow is not wrong.

Is the link in a comment, forum post, user profile, or other user-submitted content? Use rel="ugc" or rel="nofollow". Same deal — ugc is more specific, nofollow still works.

Is the link one you're placing editorially but you don't fully trust the destination? Maybe it's a source you're citing but you're not sure about the site's reliability. Use rel="nofollow".

Is the link a normal editorial reference to a reputable source? Don't use any rel attribute. Let it be a standard dofollow link. This is how the web is supposed to work — you're vouching for good content, and that's exactly the kind of link signal Google wants to see.

For WordPress users specifically, the platform handles a lot of this automatically. Comment links get nofollow (and ugc in recent versions). But links you add within your post content are dofollow by default, which is usually what you want. If you need to add nofollow or sponsored to a link in your content, most modern editors let you toggle it in the link settings. In the block editor, click on a link, go to advanced settings, and you'll see an option to add rel attributes. Or you can switch to the HTML view and add them manually. Our article on How to Handle Links During a Site Migration explores this idea in more depth.

If you're building a site from scratch or managing a custom CMS, make sure your templates automatically apply the appropriate rel attributes. Comment systems should add rel="ugc nofollow" by default. Ad placements and sponsored content blocks should include rel="sponsored". And your regular editorial content should use clean, unmodified links unless there's a specific reason not to.

<!-- Regular editorial link - no rel attribute needed -->
<a href="https://reputable-source.com/study">according to this study</a>

<!-- Paid/affiliate link -->
<a href="https://product.com?ref=mysite" rel="sponsored">check out this tool</a>

<!-- Comment or forum link -->
<a href="https://user-site.com" rel="ugc">Visit my blog</a>

<!-- Link you don't trust or want to endorse -->
<a href="https://sketchy-source.com" rel="nofollow">this claim</a>

One edge case worth mentioning: internal links. You should almost never use nofollow, sponsored, or ugc on links pointing to other pages on your own site. There was a time when SEOs experimented with "PageRank sculpting" — using nofollow on certain internal links to control how authority flowed within a site. Google effectively killed that strategy when Matt Cutts confirmed in 2009 that nofollowed internal links still caused PageRank to evaporate rather than being redistributed to the remaining dofollow links. The authority just disappeared into a void. So nofollowing your own internal links is almost always a bad idea. The one exception might be login pages or other administrative pages you don't want Google to waste crawl budget on, but even that's debatable. Most people are better off just using clean dofollow links internally and managing crawl priorities through robots.txt or meta robots directives.

Another thing I see people wonder about: does the placement of the rel attribute matter? Does it make a difference whether it comes before or after the href? No. HTML attributes within a tag are order-independent. <a rel="nofollow" href="..."> and <a href="..." rel="nofollow"> are identical as far as browsers and search engines are concerned. Same with whether you use single or double quotes. Makes no difference. The HTML spec is flexible on this.

And what about JavaScript-rendered links? If your link is generated client-side through JavaScript, the rel attribute still applies — but only if Google renders the JavaScript and sees the final HTML. Google's gotten much better at JavaScript rendering in recent years, but there can be delays. Server-side rendered links with rel attributes are processed immediately during crawling. JavaScript-rendered links might not be processed until Google's rendering queue gets to your page, which could take days or longer. If ensuring that Google sees your rel attributes quickly is important (especially for sponsored links where compliance matters), server-side rendering is the safer path.

I realize I've gone on at some length here, and some of you probably came to this article wanting a three-sentence answer. So here it is. Mark paid links with rel="sponsored". Mark user-generated links with rel="ugc". Use rel="nofollow" as a general-purpose "I don't endorse this" signal, and don't use any of them on regular editorial links to trustworthy sources. This is genuinely simpler than people make it. Three attributes, three use cases, and a whole lot of overthinking that you can skip entirely once you understand what each one actually means.