THE WEB STANDARDS GROUP
RECOMMENDS that Web pages be designed to work with
the browsers that approximately 90% of our visitors use. Current usage
is based on www.ucsb.edu domain stats. As of February, 2009, approximately 90% of our visitors were
using these browsers and platforms:
Because browser usage evolves over time, this page will be
updated periodically.
Note that the above statistics are based on server log analysis of the
http header variable "user-agent" which is a reasonable (but not completely accurate) measure of the browser and platform combination of the visitor. Although a target of 90% of 1,500,000 page views excludes 150,000 views, nearly 2000 apparently unique user agents only account for 1% of page views.
It is also possible that an immeasurable portion of the diminished hits may belong to the ninety-percentile group because the log files have errors or incomplete records. The log analysis application Webalizer produced these statistics and attempts to determine the user-agent even if the log record is incomplete. When the number of page views per user-agent is plotted, the graph has a long "tail," thousands of user-agents accounting for less than one percent of the total number of views.
The following graph (roughly to scale), attempts to illustrate this concept, a long tail of presumably unique user agents but with diminished numbers of actual page views.
Feb2009-concept-graph (pdf)
For BrowserCam and other validation tools, see our Site Tools
page at http://www.ucsb.edu/webguide/resources/tools.shtml.
The standards described on this page may be used for vendor
requirements; e.g., "Product must work with approximately 90% of
our current usage."
