rel=nofollow, sponsored and ugc: qualifying outbound links

This guide is built from Google Search Central: Qualify your outbound links to Google, the link spam section of the spam policies for Google web search, Link best practices for Google, Prevent user-generated spam, and two Search Central blog posts: Evolving "nofollow" (September 2019) and A reminder on qualifying links (July 2021). Quotes are Google's.

Links between your own pages and how to write anchor text are in our internal linking guide. The full list of Google's spam policies is in our spam policies guide. This page is about the three rel values you add to links that point to other sites: what each one tells Google, and which links need one.

sponsored, ugc and nofollow at a glance

Each value goes in the rel attribute of an <a> tag, for example <a rel="sponsored" href="https://example.com/">. Google's qualify-outbound-links page describes them like this:

Value	Use it for	Google's wording
rel="sponsored"	Ads, paid placements, sponsorships, affiliate links	"Mark links that are advertisements or paid placements (commonly called paid links) with the sponsored value."
rel="ugc"	Links that visitors add: comments, forum posts, reviews	"We recommend marking user-generated content (UGC) links, such as comments and forum posts, with the ugc value."
rel="nofollow"	Everything else you don't want to vouch for	"Use the nofollow value when other values don't apply, and you'd rather Google not associate your site with, or crawl the linked page from, your site."

nofollow is the oldest of the three. The 2019 post says it was introduced in 2005 "as a means to help fight comment spam" and became one of Google's recommended ways of flagging sponsored links. sponsored and ugc were added in September 2019 so site owners could say more precisely why a link is qualified.

Most links need no rel value

For "regular links that you expect Google to fetch and parse without any qualifications, you don't need to add a rel attribute." Google's link best practices go further: linking out "isn't something to be scared of; in fact, using external links can help establish trustworthiness (for example, citing your sources)." Google suggests nofollow "only when you don't trust the source, and not for every external link on your site." Its own example is writing a reply to an article you disagree with, when you don't want to give that site "some of your reputation from your link".

So a link to a supplier's site, a source you quote or a partner you recommend unpaid can stay a plain link. Adding nofollow to every outbound link is not what Google asks for.

They are hints, not commands

Before 2019, Google "would not count any link marked this way as a signal to use within our search algorithms." That changed: "All the link attributes—sponsored, ugc, and nofollow—are treated as hints about which links to consider or exclude within Search." Google's reason is that links carry useful information, such as "how the words within links describe content they point at," and help it understand "unnatural linking patterns".

In practice Google says the move "won't change the nature of how we treat such links" in most cases: "We'll generally treat them as we did with nofollow before and not consider them for ranking purposes." For crawling and indexing, nofollow became a hint on March 1, 2020.

Two consequences follow. First, "Links marked with these rel 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." Second, nofollow is not a way to keep a page out of Google. The 2019 post calls relying on nofollow for that "never recommended". Use noindex instead.

Paid, affiliate and gifted links

Google's link spam policy defines link spam as "creating links to or from a site primarily for the purpose of manipulating search rankings." Its examples of buying or selling links for ranking purposes include:

• "Exchanging money for links, or posts that contain links"
• "Exchanging goods or services for links"
• "Sending someone a product in exchange for them writing about it and including a link"

The list also covers "Text advertisements or text links that don't block ranking credit", advertorials where "payment is received for articles that include links that pass ranking credit", and "Requiring a link as part of a Terms of Service, contract, or similar arrangement without allowing a third-party content owner the choice of qualifying the outbound link".

Paid links themselves are allowed. Google "does understand that buying and selling links is a normal part of the economy of the web for advertising and sponsorship purposes. It's not a violation of our policies to have such links as long as they are qualified with a rel="nofollow" or rel="sponsored" attribute value". For this purpose the two are "treated the same", though sponsored is preferred.

The 2021 post applies this to two common cases:

• Affiliate links. "In general, using affiliate links to monetize a website is fine." Google asks for rel="sponsored" "regardless of whether these links were created manually or dynamically."
• Sponsored and guest posts. Google strongly recommends the right rel values on these links too. When it detects "excessive sponsored and guest posting without proper link tags, algorithmic and manual actions may be applied". This applies both to sites that publish these posts and to sites that get links from them.

A manual action shows up in Search Console, and our manual actions guide covers how to fix one and ask for a review. The rel value is only the search side. A paid post or a gifted product may also need a visible ad label for readers, which is covered in our influencer marketing disclosure guide.

Comments, forums and reviews

If visitors can post links on your site, those links should carry ugc (or nofollow). Google's user-generated spam page says: "Since oftentimes spammers are motivated by leaving a link to their site, consider adding a nofollow or ugc rel attribute to all links in untrusted content." The same page suggests adding noindex to posts from new users "that don't have any reputation on your platform" until they earn it.

Google also allows the reverse: "If you want to recognize and reward trustworthy contributors, you might remove this attribute from links posted by members or users who have consistently made high-quality contributions over time." Spammy forum comments are one of the link spam policy's examples ("Forum comments with optimized links in the post or signature"), so ugc protects your site as well as qualifying the link. Spam sent through contact and signup forms is a separate problem, covered in our form spam guide.

Combining values, and using the wrong one

You can use more than one value, "as a space- or comma-separated list", for example rel="ugc nofollow". Google's 2019 post says rel="ugc sponsored" is "a perfectly valid attribute", and that adding nofollow next to the newer values is fine "if you wish to be backwards-compatible with services that don't support the new attributes."

Existing nofollow links don't need changing: "There's absolutely no need to change any nofollow links that you already have." For ads flagged with nofollow, Google recommends "switching over to rel="sponsored" if or when it is convenient."

Only one mistake really matters. "There's no wrong attribute except in the case of sponsored links." Marking a normal link as sponsored at most means Google "might not count the link as a credit for another page." Leaving the label off a paid link is the risky direction: "Any link that is clearly an ad or sponsored should use sponsored or nofollow".

Not for your own pages

These values are for links to other sites. Google says that if you need to stop it fetching a link to a page on your own site, "use the robots.txt disallow rule," and to keep a page out of the index, "allow crawling and use the noindex robots rule." Both are covered in our robots.txt and XML sitemaps guide and noindex guide.

The rel values only work in <a> elements that Google can crawl. The exception is nofollow, "which is also available as robots meta tag" and then applies to every link on the page.

noopener and noreferrer are different

Many sites add rel="noopener" or noreferrer to links that open in a new tab. These are browser settings, not search hints. MDN's rel reference describes noopener as stopping the new page from getting an opener reference, and noreferrer as meaning "No Referer header will be included". nofollow, by contrast, "Indicates that the current document's original author or publisher does not endorse the referenced document."

They can sit in the same attribute, for example rel="sponsored noopener". With noreferrer the linked site can't see that the visit came from you, which matters for affiliate and partner links that are credited by referrer. To track your own campaign links, use UTM parameters instead.

How we set links up

This part is our own practice, not Google guidance. On business sites we build:

• Editorial links to sources, suppliers and partners stay plain links.
• Affiliate links, paid directory listings, sponsored posts and links given in return for a product or a discount get rel="sponsored", set in the template or the link plugin so a new link can't miss it.
• Blog comments, reviews and forum posts get rel="ugc nofollow" by default, which most CMSs already do for comments. We check it is still there after a theme change.
• When a client buys a sponsored article or a listing on another site, we ask the publisher to mark the link as sponsored. Google's policy covers sites that acquire links as well as sites that publish them.

To see who links to your site, use the Search Console Links report.

Frequently asked questions

Should I use sponsored or nofollow for paid links?

Either is acceptable, and Google treats them the same for avoiding link spam actions. Google prefers sponsored because it says why the link is qualified.

Do I need to replace my old nofollow links?

No. Google says there is no need to change existing nofollow links. Use sponsored for new paid links when it is convenient.

Should every external link be nofollow?

No. Google suggests nofollow only for sources you don't trust, not for every external link. Linking to good sources can help show that your content is trustworthy.

Does nofollow stop Google from crawling or indexing the linked page?

Not reliably. Since March 1, 2020 nofollow is a hint for crawling and indexing too, and Google can still find the page through sitemaps or other sites' links. Use noindex to keep a page out of the index.

Do affiliate links need rel="sponsored"?

Google asks sites in affiliate programs to qualify these links with rel="sponsored", whether they were added by hand or generated automatically. Affiliate links that are not qualified can lead to manual or algorithmic actions.

Want your site's links, templates and comment settings set up so this happens on its own? See our website development and website maintenance services, all our services, or the rest of our guides.