According to a new post on the Google Webmaster Central blog, the supplemental index is no longer, well, supplemental. Google has long had a two-tiered index and webmasters have generally feared the second, supplemental tier. A Forbes article earlier this year called it “Google Hell“, as historically, those pages weren’t crawled as often as those in the main index, weren’t returned in search results unless the main index didn’t contain enough matching pages, and were labeled “supplemental,” which implied they were inferior to the other results.
In July, Google removed the supplemental label, saying that they had overhauled the supplemental crawling and index system and therefore the label was no longer needed. Now, they say that the next set of improvements are complete and that they now search both the main and supplemental index for all queries, not just the long tail queries that the main index can’t satisfy.
In the post, Google explains the origin of the supplemental index, saying that it was meant to provide a better user experience for searchers looking for obscure queries. However, over time, the supplemental index grew to something that webmasters tried to avoid, as they felt that it kept their pages from being shown for relevant queries. In addition, Google didn’t refresh those pages as often as it did those in the main index.
With this latest change, Google says that searchers will see a larger set of relevant documents from a deeper slice of the web in results, particularly for non-English queries. Supplemental pages that previously had little chance of ranking now will be queried and scored for relevancy along with the rest of the pages in the index, and will now potentially have a much better chance of being shown.
What does this mean for the webmaster? In the July post, Google said they would be rolling out this change incrementally, so changes a site owner would see may already be in place. Webmasters who had previously noticed that their pages in the supplemental index weren’t being recrawled frequently should have been noticing steady improvements in crawl frequency and indexing freshness in the recent months. It’s doubtful that today’s blog post is a signal for a dramatic change in overall ranking, but it’s worth keeping an eye on the pages that webmasters had previously given up hope on due to their supplemental status to see if hope reigns eternal, after all.