The aim of this paper is to model and study the age of the Web using a sample of about four million of web pages from the
16 European Research Area countries obtained during 2004 and 2005. Web page time-stamp (date when the web pages were created
or last changed for last time), format and size in bytes data have been analysed. Several indicators are introduced to measure
longitudinal aspects of the Web. Half-age is proposed as a measure of the age distribution because this is found to be exponential.
“Web Update Index” and “Lifespan Index” are introduced to measure the changing rate of a small sample over time. Results show
that the British Web space has the youngest Web pages while the Greek and Belgian ones have the oldest. The study also compared
Web pages topics and found that Biology pages are more stable than Physics pages.