Google announced that its index reached 1 billion web pages in 2000. On June 26, 2000, the company announced an index containing more than 1 billion URLs, making it the largest search index publicly available at the time.
The milestone needs a small historical qualification. Google described 560 million URLs as fully indexed for text search and another 500 million as partially indexed, while the broader index exceeded 1 billion URLs. Later Google accounts summarized this achievement by saying that the Google index reached the one-billion mark in 2000.
This growth was rapid. Google's first index, created in 1998, contained about 26 million pages. By the end of 2000, a company announcement said its index had grown beyond 1.3 billion indexed web pages and was supported by more than 6,000 Linux-based servers.
Readers sometimes confuse indexed pages with all pages on the Web. Search engines discover URLs, but duplicates, automatically generated pages, inaccessible content, and other technical factors mean an index is not a complete census. Google's later trillion-URL milestone counted discovered unique URLs, a different measure from searchable pages.