Typing HELP from QuickExec takes you to a page that does not document how to view or set prefs. It goes to http://docs.telerik.com/fiddler/knowledgebase/quickexec. The prefs doc is at http://fiddler.wikidot.com/prefsaction Also, add a link to send feedback onto the KB pages / documentation to make it easy to submit doc feedback :-) Cheat sheet: prefs set fiddler.importexport.HTTPArchiveJSON.MaxTextBodyLength 999999 prefs show fiddler.importexport.HTTPArchiveJSON.MaxTextBodyLength