What are the different HTML rel Attributes in SEO? Regarding SEO, every tiny detail in your website’s code matters. One such detail is the rel attribute in HTML links. The rel (short for relationship) tells search engines like Google the connection between your webpage and the linked page. Used correctly, rel attributes can: Control the flow of PageRank (a.k.a. “link juice”). Maintain site security. Avoid duplicate content issues. Improve user experience on multilingual or community-driven websites. This blog will explore the different types of rel attributes in SEO, with real-world examples related to www.sanoopbalan.com. 1. rel=”nofollow” The nofollow relationship is the most commonly used attribute in SEO, A nofollow tag is used to prevent search engines from establishing any kind of relationship between the site giving the link back to the other website, a common way of saying “we do not endorse the link we are connected to the external site.” This tag can only be used when sponsored, and UGC are not applicable, which we will discuss below. The crawlers will understand that the website owners are not providing any recommendations to the link they are pointing to, which will then indicate that no ranking credits should be passed to the pointed website Purpose: Instructs search engines not to pass PageRank to the linked page.Use cases: Links to untrusted sites. User-generated links (comments/forums). Paid links (if not using sponsored). Example (linking to an external site from a blog in sanoopbalan.com): <a href=”https://randomwebsite.com” rel=”nofollow”>Check this source</a> Here, Google won’t pass any authority from sanoopbalan.com to randomwebsite.com. 2. rel=”sponsored” The rel=”sponsored” attribute is an HTML link attribute introduced by Google in 2019 to enhance the evaluation of link quality. It helps search engines clearly identify paid or promotional backlinks that compensate you in different ways, including a hyperlink (backlink) to their website. Before 2019, all paid links had to be tagged with rel=”nofollow”. However, Google later refined this system and introduced two new attributes among the two attributes we are currently discussing about sponsored relationships. If we declare properly, the attribute signals to Google that the link was not earned organically but is part of a commercial agreement. Purpose: Explicitly tells search engines that the link is paid, affiliate, or promotional. Use cases: Sponsored guest posts. Affiliate links. Banner advertisements. Example (say, you promote a digital marketing tool): <a href=”https://marketingtool.com” rel=”sponsored”>Best SEO Tool</a> This ensures compliance with Google’s paid links policy while allowing users to click. Why rel=”sponsored” is Important. Transparency: Distinguishes between editorial (earned) backlinks and paid placements. Compliance with Google’s Webmaster Guidelines: Paid links without this attribute may lead to a Google penalty for link schemes. Fair Ranking Signals: Prevents websites from manipulating PageRank through buying backlinks. Affiliate Marketing Compliance: Most affiliate links are now recommended to be tagged as rel=”sponsored”. When to Use rel=”sponsored” Sponsored posts/advertorials on blogs and news websites. Banner ads or promotional placements. Affiliate links (Amazon affiliate, CPA offers, etc.). Paid product reviews where the brand compensates the publisher. Partnership links in collaborations where there is a monetary or material exchange. Links with rel=”sponsored” do not transfer PageRank or link juice. They still serve as referral traffic sources, but won’t boost organic ranking. Google treats them similarly to nofollow, but with a more apparent intent 3. rel=”ugc” (User-Generated Content) he rel=”ugc” attribute was introduced by Google in 2019 alongside rel=”sponsored”. Its purpose is to differentiate links created by users (not the website owner) from editorially placed links. User-generated content (UGC) is a massive part of the web, including blog comments, discussion forums, Q&A platforms, and social communities. Since website owners don’t always control these links, they can easily be abused for spammy link building. rel=”ugc” stands for User Generated Content. It marks links placed in public content areas where users contribute content instead of the website’s editorial team. It helps Google understand that the website owner is not endorsing these links. Purpose: Identifies links added by users (not the website owner). Use cases: Blog comments. Forum posts. Community-driven platforms. Example (in a comment section of sanoopbalan.com): <a href=”https://userwebsite.com” rel=”ugc”>My Website</a> This way, even if a spammy user adds a link, Google won’t treat it as an editorial vote from your site. Why rel=”ugc” is Important. Spam Prevention: Prevents spammy comment backlinks from passing SEO value. Transparency: Clearly tells Google that the site owner didn’t editorially place or approve the link. Guideline Compliance: Keeps websites safe from penalties related to comment spam or forum spam. When to Use rel=”ugc.” Blog comments (e.g., WordPress comment sections). Forum posts & replies (e.g., Quora, Reddit-style communities). Q&A sites (e.g., StackOverflow user answers). Profile bios/signatures in community platforms. Review sections where users can add links. Better Link Classification: Improves how search engines evaluate link quality across the web. 4. rel=”canonical” The canonical tag (rel=”canonical”) is an HTML element used to help search engines understand which version of a page should be considered the original or preferred version. In SEO, duplicate content can confuse search engines. If the same or similar content exists across multiple URLs, Google may not know which one to rank. The canonical tag solves this issue by pointing to the “master” page. rel=”canonical” tells search engines, “This page is a duplicate (or variation), but the preferred page to index and rank is the one I’m specifying.” It’s like saying: “Don’t split ranking signals across duplicates. Give all authority to this page instead.” Purpose: Avoids duplicate content by telling Google which version of a page is the preferred one. Use cases: Duplicate content under multiple URLs (with/without UTM tags, session IDs, etc.). Pagination or product variations. Example (if both these URLs exist): https://www.sanoopbalan.com/seo-guide https://www.sanoopbalan.com/seo-guide?utm_source=facebook Canonical tag inside <head> of the duplicate page: <link rel=”canonical” href=”https://www.sanoopbalan.com/seo-guide” /> Google consolidates signals to the main URL. Why Canonical Tags Are Important Duplicate Content Control: Prevents duplicate content penalties or dilution of ranking signals. Consolidation of Link Equity: Ensures backlinks pointing to different page versions are credited to a single, canonical URL. Better Crawl Efficiency: Helps search engines avoid wasting crawl