Danny Sullivan has details of a new study that tries to estimate the size of the web and what percentage the search engines have indexed so far. Google is per usual the leader of the pack.
The paper, from Antonio Gulli of Università di Pisa (who is also director of advanced products for Ask Jeeves) and Alessio Signorinialso of the University of Iowa, estimates what percentage of the Web is covered by each search engine:
| Search Engine | Self-Reported Size (Billions) | EstimatedSize (Billions) | Coverage of Indexed Web (%) | Coverage of Total Web (%) |
|---|---|---|---|---|
| 8.1 | 8.0 | 76.2 | 69.6 | |
| Yahoo! | 4.2 (est.) | 6.6 | 69.3 | 57.4 |
| Ask | 2.5 | 5.3 | 57.6 | 46.1 |
| MSN (beta) | 5.0 | 5.1 | 61.9 | 44.3 |
| Indexed Web | N/A | 9.4 | N/A | N/A |
| Total Web | N/A | 11.5 | N/A | N/A |
| Note: "Indexed Web" refers to the part of the Web considered to have been indexed by search engines. | ||||
The first thing you wonder is whether any of the search engines are lying about their size. Google claims to have the biggest search index, 8.1 billion pages. The estimate shows Google’s claim is pretty much on target. The same holds true for MSN and Ask Jeeves.