1 trillion unique URLs on the Web

[nandagopal]

Google is now reporting that its seen more than 1 trillion unique URLs on the Web. That's a big number and a massive jump from the 26 million URLs it saw in 1998.  But even at a trillion pages Google admits that there are many duplicates (in terms of content), and that there well may be an infinite number of pages overall.
Many pages have multiple URLs with exactly the same content or URLs that are auto-generated copies of each other. Even after removing those exact duplicates, we saw a trillion unique URLs, and the number of individual Web pages out there is growing by several billion pages per day.

So how many unique pages does the web really contain? We don't know; we don't have time to look at them all