Link attributes, in an SEO context, are values of the rel attribute on an <a> element that describe how a link relates to its target. Searches for the term often return the general HTML attributes of the <a> element, such as href or target, or the <link> element in the page head. This entry covers only rel on links.
Which values matter for SEO
Google names three values to qualify outbound links. sponsored marks advertisements and paid placements. ugc marks links in user-generated content such as comments and forum posts. nofollow applies when neither fits and the site would rather not be associated with the target. Google says nofollow stays acceptable for paid links.
MDN also lists noopener and noreferrer. They change what the browser does when a link opens, for instance whether the target page can reach window.opener or receives a Referer header. They are unrelated to ranking.
| Value | Purpose according to Google | Required? | How Google treats it |
|---|---|---|---|
no rel value (often called "dofollow") | regular link that Google is expected to fetch and parse without qualification | –; Google has no dofollow value | Google can follow and parse the link |
rel="sponsored" | advertisements and paid placements | for paid links, sponsored (preferred) or nofollow; otherwise link spam under the spam policies | hint; links with this value are generally not followed |
rel="ugc" | links in user-generated content such as comments and forum posts | recommended; can be removed for members with a consistent record of high-quality contributions | hint; links with this value are generally not followed |
rel="nofollow" | when no other value applies and you'd rather Google not associate your site with the target or crawl it from your site | no; still acceptable for paid links | hint, for ranking since 10 Sept 2019 and for crawling and indexing since 1 March 2020 |
nofollow as a robots meta rule | don't follow the links on this page | no | applies to every link on the page |
Target pages can still be found and crawled through sitemaps or links from other sites. Several values can be combined, separated by spaces or commas, for example ugc nofollow. For links within your own site, Google points to a robots.txt Disallow rule, and to noindex for keeping a page out of the index. Sources: Google Search Central: Qualify your outbound links to Google (last updated 2025-12-10); Google Search Central: Spam policies for Google web search, link spam (last updated 2026-08-28); Google Search Central Blog: Evolving "nofollow" – new ways to identify the nature of links (2019-09-10); Google Search Central: Robots meta tag specifications, nofollow. Last checked: .
Example
<a href="https://example.com/partner" rel="sponsored">Partner offer</a>
<a href="https://example.com/forum" rel="ugc nofollow">Forum link</a>
Several values can share one attribute, separated by a space. Google also accepts a comma-separated list.
Sources
- Qualify your outbound links to Google – Google Search Centraldevelopers.google.com
- rel – MDN Web Docsdeveloper.mozilla.org
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