How often do the rates on this website update?

Rates in the European Central Bank reference set are based on data published once per business day. The ECB does not publish a new reference rate on weekends or its holidays, so the most recent available publication is shown on those days.

Currencies outside that set use an extended data source with its own publication schedule. The source, publication date and status shown with a figure tell you which data you are reading and how current it is.