Facebook will implement a long delayed tab width reduction on Pages. The official reductions begins today. The change has been announced by Facebook back in October 2009, but was delayed.

After the reduction, the maximum width for any Page tab is 520 pixels, down from 760 pixels. Applications and canvas pages will need to be reformatted or else they will appear broken. The change has been rolled out slowly in part to let brands, agencies, page management companies and other marketers finish running campaigns that relied on the wider tab size.