Objects on a web page are associated with stored records indicating historical object usage. Associations between objects and records take into account discrepancies in object identifiers resulting from authorial edits and/or differences in browser assignment of object identifiers. An object having an object identifier that differs from that of a stored record by not more than a predetermined tolerance value, and that has other indicia that match the stored record, is considered to match the stored record. Reports are generated quantifying web page object usage, for example by superimposing color shadings or other visual indicia on a representation of a web page.