If buffering is enabled, then you can access fwx output content (to determine its size, do search and replace, etc.) in the property Response.OutputContent. One option would be to add code to your fw_exit.exe that automatically appends the size at the end of each HTML page:
Sent by Anthony Shipley on 07/14/2003 06:42:16 AM:
I think I've found one difference between these two alternatives.
With building the page into the html_out variable, it is also possible to insert at the end the size of the page.
I can't think how to achieve that (easily) within a .fwx file.
Any suggestions appreciated.