Noindex
A rel=”noindex” directive is used to instruct search engines not to include a page within their index, to prevent it from appearing within search results. Our SEO Office Hours Notes below explain the use of this directive, along with further advice compiled from Google’s Office Hours sessions and real-world examples.
For more on noindex directives, check out our article: Noindex, Nofollow & Disallow.
Noindex Pages Pass Authority but Might Be Dropped over Time
A noindexed page can still pass link authority through its followed links, but if it remains noindexed for a long time, Google may drop the page and the authority will be lost.
404 Pages Can be Reindexed as New Page Unlike Noindex
If a page has been permanently removed by responding with an error, if it comes back, the page will be treated like a new page, unlike a noindex.
Use Noindex or Canonical on Faceted URLs Instead of Disallow
John recommends against using robots.txt disallow to prevent facet URLs from being crawled as they may still be indexed, and allow them to be crawled and use a noindex or canonical tag, unless they are causing a server performance issue.
Return 404 or Noindex for Empty Pages
Google prefers you to return a 404 status or add a noindex for empty pages, like category pages with no items listed, even if temporary.
Noindex Pages are Indexed but Suppressed from SERPS
Noindex pages are still in the index, they are just suppressed from appearing in search results.
Don’t Use Noindex on Canonicalised Pages
Don’t use a Noindex on canonicalised pages, because if Google accidentally picks this as the canonical, nothing will show up in search results.
Google Ignores Noindex in Image File Headers
Googlebot Doesn’t See Robots Meta Tags on Redirected URLs
If a page is a redirected, Google won’t see any robots meta tags on the page, although they might see a noindex in the headers.
Noindex Pages Won’t Be Crawled Eventually
If a page is Noindex for a long time, Google may stop crawling the page so it can’t pass PageRank.
Don’t Use Noindex on Canonicalised Pages
Don’t mix Noindex with canonical to a different page.