Francesco Mapelli has recently launched a new SEO tool called the Supplemental Index Ratio Calculator which allows site owners to check the percentage of pages from their site that are included in the Google Supplemental Index.
What is the Supplemental Index Ratio?
Google has a secondary index containing pages of less importance. This pages are considered supplemental results, and returned in SERPs only if there are no pages from the main index matching the given search term(s). The Supplemental Index Ratio simply gives you the percentage of pages indexed from your website that are in the supplemental index. The lower your Supplemental Index Ratio, the better it is for your website.
How does the Supplemental Index Ratio Calculator work?
Supplemental Index Ratio Calculator uses the simple Google site search (with &filter=0 ) to calculate the total number of pages that are in the total index (main + supplemental).
Then with it adds the ‘+-inallurl%3Awww.yoursite.com’ extension to find the total number of pages that are in the main index (at the end of this list you will see “In order to show you the most relevant results, we have omitted some entries …â€).
After that the author of the script, Francesco uses some basic math to find out what percentage of pages are in the supplemental index. As you may notice, in the second query there’s a strange operator “inallurl:www.domain.com†which is not a real Google operator. In reality this operator does not exist, it’s just an hack to have Google trigger his supplemental filter. You can use “xyz:www.domain.com†and the results will be the same.
