An older Google term for lower-priority indexed pages.
Have you ever felt like you have a page that is really great, but Google just seems to ignore it? It can feel like your content is stuck in a digital basement, waiting to be found. I am here to shed light on a concept that helps explain this frustration. We are going to explore What is a Supplemental Index? so you can learn how to make sure your most important pages get into Google’s A-list storage.
What is a Supplemental Index? The Search Engine’s Backroom
What is a Supplemental Index? It is a historic term for a secondary database where search engines used to store web pages they considered less important. Think of it as a library’s backroom, holding books that are still indexed but rarely placed on the main, frequently-searched shelves. Pages here are less likely to show up in common search results.
What Gets Sent to the ‘Backroom’
While the actual system is now more integrated, the idea remains: pages with low value, duplicate content, or very few internal links are treated as less important. Google wants its main index to be fast and high-quality for common searches. I focus on creating unique, detailed content to ensure pages are never seen as low priority.
Supplemental Index Risks and Your CMS Platform
Your CMS does not cause a supplemental index issue, but poorly managed content on any platform can trigger it. The main goal is to ensure your CMS does not accidentally create thousands of low-value pages. You must prevent the indexing of repetitive, thin content.
Content Management to Avoid Low Priority
WordPress can generate duplicate content from tags and archives, so I always recommend using a good SEO plugin to apply “noindex” tags to those low-value pages. Shopify users must be careful with automatically generated filter and sorting pages that create duplicate listings. Wix and Webflow generally manage these technical issues well, but you must ensure every page has unique, substantial content. For custom CMS, you need a developer to check and optimize your robots.txt file to block indexing of any non-essential, thin pages.
Avoiding the Supplemental Index Across Industries
You can structure your content to guarantee importance, no matter your industry focus.
Ecommerce
E-commerce sites risk low priority for product pages with thin content copied from a manufacturer’s site. I advise you to write unique, detailed descriptions for every product to add distinct value. Also, use the rel=canonical tag to point search engines to your preferred version of similar product pages.
Local Businesses
Local businesses might have issues with duplicate content if they create similar landing pages for every city or neighborhood. Make sure each location page has unique text, local photos, and specific local information. This shows Google that each page serves a unique purpose for a local searcher.
SaaS (Software as a Service)
SaaS companies must ensure their ‘About Us’ and ‘Team’ pages have unique, high-quality content that builds trust and authority. I recommend linking important blog posts from your homepage or primary navigation. This clearly signals to Google that these are high-priority pages.
Blogs
Bloggers often end up with duplicate content when posts appear on both the main blog and in various category and tag archives. Use your CMS’s SEO settings to “noindex” the archive pages and only allow the main blog post to be indexed. Always update your core content frequently to show freshness and relevance.
FAQ: Making Sure Your Pages Rank
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Does the Supplemental Index still exist today?
- The original ‘Supplemental Index’ tag is no longer used by Google, but the concept of content being indexed but given low priority still exists. Pages with low quality are less likely to show in search results.
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How do I know if my page is considered low priority?
- Check Google Search Console. If a page is marked as ‘Crawled – currently not indexed’ or ‘Discovered – currently not indexed,’ Google knows about it but has chosen not to rank it.
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What is the single biggest factor to avoid low priority indexing?
- Content quality is the biggest factor. Focus on creating pages that are unique, useful, comprehensive, and provide real value to the person searching.
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Should I use the noindex tag a lot?
- You should use ‘noindex’ only for pages that offer no unique value to the user, like internal search results, thank you pages, or category archives. Never ‘noindex’ pages that you want to rank in search results.
