Someone provided me the regex to parse out a query string: (?<=\?)[^?]+$ I am trying to use that in JMeter with no luck (although I am successful in pulling out individual query string parameter values based on various example postings on the web). I created a regular expression extractor called "Grab QueryString". I selected the URL response field to check. For the reference name, I typed "myQueryString". For the regular expression, I entered your text. For template, I entered $1$ Match no = 1 Default Value = ERROR Unfortunately, "myQueryString" is getting populated with ERROR and not the URL query string as hoped when I try and use it as a parameter in a future GET. Thus, I see this in the "View Results Tree": https:/www.website.com/folder/page.aspx?ERROR Instead of: https:/www.website.com/folder/page.aspx?jfhjHSDjgdjhsjhsdhjSJHWed Did I do something wrong? Anyone have any suggestions?