Francesco Mapelli has 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.
Supplemental Index Ratio Calculator uses a normal Google site search (with &filter=0 ) to find how many pages are in the total index (main + supplemental).
Then with it adds the ‘+-inallurl%3Awww.yoursite.com’ extension to find the number of pages in the main index (at the end of this list there’s the “In order to show you the most relevant results, we have omitted some entries …”).
After that Francesco uses some basic math to find out what percentage of pages are in the supplementali ndex.
As you may notice, in the second query there’s a strange operator “inallurl:www.domain.com”. This is not a real google operator, the 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 are the same.