If you spend any time working with SEO, affiliate links, or WordPress monetization, you already know how quickly small technical details can snowball into major ranking issues. Link attributes are one of those details. They look simple, just a tiny snippet added to an HTML tag, but they carry real weight in SEO, compliance, and how search engines interpret the structure of your site.
In this guide, I’ll break down the key link attributes that matter today: rel="nofollow", rel="sponsored", and rel="ugc". I’ll look at how they work, their initial mission, and what publishers need to know to stay compliant without accidentally leaking valuable link equity.
The rel attribute (short for “relationship”) is part of the standard HTML <a> tag. Its job is to describe the relationship between the current document and the target page. In practice, you add it directly to the link tag, for example:
<a href="https://www.example.com" rel="nofollow">Link text</a>While marketers often associate rel attributes solely with SEO, they have always been much broader than that. Web developers use them for:
rel="stylesheet")rel="alternate" hreflang="x")rel="prev" / rel="next")Within this wide family, nofollow, sponsored, and ugc form a specific subgroup designed to help search engines understand link intent and manage how link equity should flow.
At the heart of link attributes is one key concept: link equity, commonly known as link juice. It represents the algorithmic authority a linking page passes on to its target. The amount of equity transferred depends on factors like relevance, domain authority, and anchor text quality.
This matters because link equity feeds directly into Google’s PageRank system and is still a confirmed ranking factor. Every link you publish essentially casts a vote. Some votes you want to give freely; others you should withhold.
By default, every link without a qualifying attribute counts as dofollow, meaning you are passing equity. With the right rel attribute, you decide when that happens and when it doesn’t.
Using the wrong attribute or omitting one where it's required can create two significant problems:
For publishers, especially those running monetized WordPress sites, link attributes are not optional. They are a key part of long-term SEO protection.
Search engines have spent years fighting link spam. To them, any unmarked paid link can be a signal of manipulation. That’s why correct attribution is a tidy SEO best practice and a direct compliance requirement.
Marking sponsored links ensures:
And while link attributes don’t guarantee ranking benefits, they do protect the authority you’ve earned. It’s essentially a defensive SEO strategy: keep your link equity where it generates the most value.
Google introduced nofollow in January 2005 to combat aggressive comment spam, especially on blogs. Initially, nofollow was treated as a directive, meaning Google would neither follow the link nor pass PageRank.
Over time, publishers also adopted it as a catch-all label for paid or sponsored links, mainly because there was no dedicated alternative.
Fourteen years later, Google refined link classification by launching two new attributes:
rel="sponsored": for paid, sponsored, affiliate, partnership, or otherwise compensated linksrel="ugc": for user-generated content like comments or forum postsThese new attributes allowed Google to distinguish commercial links from user-generated ones and from general non-endorsed links.
The biggest change arrived in 2019 and 2020. Google shifted the interpretation of all nofollow-based attributes, including sponsored and ugc, from a strict directive to a hint.
What does that mean?
Search engines may still choose to crawl, index, or algorithmically evaluate these links when they consider it useful. They’re not obligated to ignore them anymore. For publishers, the compliance rule remains unchanged: Paid links must still be clearly marked, preferably with sponsored.
The hint model simply gives Google more flexibility in understanding the broader link graph of the web.
Google’s evolution signals that the search engine wants a clearer understanding of link intent to suppress manipulation and to evaluate legitimate links in user-generated spaces better.
As a publisher, your primary responsibility is:
sponsoredugcnofollow for general non-endorsed or untrusted linksEven though attributes are now hints, search engines still expect transparent disclosure. Sponsored remains the recommended standard for monetized links, including affiliate URLs.
| Attribute | Introduced (Google) | Primary Purpose | Original Status | Current Status |
|---|---|---|---|---|
rel="nofollow" | Jan 2005 | General non-endorsement / catch-all | Directive | Hint for ranking & crawling |
rel="sponsored" | Sep 2019 | Marking paid links, ads, sponsorships, and affiliates | Hint | Hint (preferred for paid) |
rel="ugc" | Sep 2019 | Identifying user-generated content | Hint | Hint |
Using link attributes correctly requires a clear understanding of where each one fits, how they overlap, and when to prioritize one over the other. Even though they look simple on the surface, these attributes shape how search engines interpret your links, and how safely you operate within SEO guidelines.
The nofollow attribute tells search engines that you are not endorsing the linked page and that no ranking credit should be passed on. Today, with sponsored and ugc covering more specific scenarios, nofollow mainly serves as the general-purpose fallback for links where no endorsement is intended, and no other attribute applies.
You can also combine nofollow with the newer attributes, and doing so is often recommended for backward compatibility. A combination like rel="nofollow ugc" ensures that even search engines or tools that do not yet interpret ugc still treat the link as non-endorsed.
The sponsored attribute exists for one primary reason: compliance. You must clearly label any link that you create in exchange for money or other compensation like ads, sponsorships, collaborations, paid reviews.
Google prefers rel="sponsored" for all monetized links, though it still accepts nofollow. But in practice, sponsored is the safer and more transparent option, especially in affiliate marketing.
Google explicitly requires that affiliate links be marked with sponsored. It protects publishers from manual actions related to “unnatural links” and gives Google a clearer understanding of the commercial nature of your link graph. It’s good for compliance, good for transparency, and good for long-term SEO stability.
The ugc attribute applies to links within user-generated content rather than site-owner-generated content, such as comments, forums, community areas, guestbooks, and similar spaces.
Its primary purpose is to prevent link spam from silently draining your link equity. By signaling that a link originates from user-generated content, you shield your site from low-quality links often dropped by bots or spammers.
This attribute is now so fundamental that WordPress automatically assigns rel="nofollow ugc" to comment links starting from version 5.3.
There is, however, room for nuance. If a long-standing, verified community member contributes high-quality content, you may choose to remove the ugc attribute and intentionally pass equity. This can help search engines discover valuable niche references from credible users.
For publishers working with monetized content and community features, this creates a clear audit requirement: ensure affiliate links use sponsored, and ensure UGC uses ugc, ideally with nofollow as a fallback for older systems.
Link attributes serve a dual purpose: they help search engines understand the intent of your links, and they protect you from violating search engine guidelines. Both aspects matter.
Since Google reinterprets nofollow, sponsored, and ugc as hints rather than directives, the mechanics have shifted.
nofollow for crawl budget management is ineffective. If the URL is linked from anywhere else on the web with a dofollow link, Google will crawl it anyway. For strict crawl and indexing control, you should continue relying on robots.txt, meta robots, or X-Robots-Tag directives.The most critical function of sponsored and, in some contexts, nofollow is protection against penalties.
Failing to label paid links violates Google’s policies on unnatural links and can result in manual actions. This is the highest-risk scenario in link attribution.
Neglecting ugc is less likely to cause a direct penalty but can open the door to link spam, weakening your domain authority over time. The risk here is erosion, not punishment unless the abuse becomes extreme.
Bing fully supports rel="nofollow", rel="sponsored", and rel="ugc" and, unsurprisingly, also encourages labeling paid links. If you comply with Google’s rules, you are effectively compliant with Bing by default.
However, link attributes should not be misused to manipulate internal link equity.
The old practice known as PageRank sculpting, where internal links were artificially nofollowed to funnel authority more strategically, is now considered ineffective. Google’s interpretation ensures that internal nofollows do not preserve additional PageRank. They simply waste it.
Your internal navigation, category pages, and editorial content should remain dofollow to ensure link equity flows naturally across the site.
Best practice matrix for link qualification:
| Link Type | Compliance Status | Recommended Attribute | Goal |
| Paid links/ads | Must be labeled | rel="sponsored" (preferred) | Prevents penalties for unnatural links |
| Affiliate links | Must be labeled | rel="sponsored" | Transparency, avoids penalties, marks monetized intent |
| Blog comments/forum posts | Should be labeled | rel="ugc" or rel="ugc nofollow" | Controls trust, prevents spam-related PageRank loss |
| Editorial, non-endorsed links | Optional “catch-all” labeling | rel="nofollow" | Signals a lack of endorsement |
| Internal navigation links | Should remain dofollow | None | Ensures optimal internal link equity flow |
While nofollow, sponsored, and ugc remain the primary signals for communicating link intent to search engines, several other rel-attributes offer valuable security and privacy benefits.
A fundamental security measure for every link opened in a new tab. It prevents reverse tab-napping by blocking access to window.opener and protects your site from malicious scripts running on the destination page.
Designed for privacy and analytics control, this attribute hides the referring URL from the destination site. Because it provides the same security protections as noopener and additionally suppresses referrer data, it is often paired with rel="noopener noreferrer". Most CMS platforms, including WordPress, automatically apply noopener when using target="_blank", but adding noreferrer remains useful when referrer privacy is a priority.
These attributes do not directly influence rankings, but they contribute significantly to your site's overall technical integrity and trustworthiness, especially when linking to third-party websites.
Once you start dealing with larger volumes of ads, consistent link-attribute implementation becomes less of a “nice to have” and more of a structural requirement. The most reliable approach combines clean manual coding with smart automation across your WordPress environment.
Link attributes are placed directly within the <a> tag of your HTML markup.
<a href="https://advertisement-partner.com/product" rel="sponsored">Ad</a>If you need to combine values, separate them with spaces. A markup such as rel="ugc nofollow" is perfectly valid and ensures that even older crawlers or SEO tools treat the link as unaffiliated. It is helpful in mixed environments where not every attribute is yet universally recognized.
<a href="https://advertisement-partner.com/product" rel="ugc nofollow">Ad</a>Whenever a link opens in a new tab (target="_blank"), you should also apply rel="noopener" to prevent tab-napping attacks. This simple line of defense blocks the new page from interacting with the originating window.
<a href="https://advertisement-partner.com/product" rel="noopener sponsored" target="_blank">Ad</a>For larger publishing operations, automation is the only sustainable way to maintain compliance and minimize human error. Ad-management plugins play a crucial role here by centralizing control over link attributes and guaranteeing uniform application across all ads.
With AdPresso, you can define global default link attributes once and override them on an ad-by-ad basis whenever needed. This keeps your setup streamlined and prevents inconsistencies that could otherwise slip in during manual edits. See the AdPresso link attribute manual to learn how to integrate it within a few clicks.
Link attributes have evolved into a multifaceted control layer connecting SEO, legal compliance, and brand reputation. From this perspective, the strategic priorities become clear. For any form of monetized linking, particularly advertising and affiliate placements, rel="sponsored" stands out as the most transparent, policy-aligned, and future-proof choice. Consistent usage significantly reduces the risk of manual penalties tied to link schemes and offers stronger compliance signals than relying on nofollow alone.
Although Google now treats these attributes as “hints” rather than absolute directives, they remain essential for transparent disclosure and proper classification of paid placements. It is equally important to remember that internal links should always remain dofollow. Attribute manipulation is not a tool for sculpting internal PageRank.
Given today's strict guidelines and the operational complexity within larger publishing setups, automated attribute management via plugins like AdPresso is the only scalable path. It ensures accuracy at every step, eliminates accidental mislabeling, and keeps your site compliant, even as your advertising footprint grows.
