qsreplace is a command-line tool that processes URLs from standard input and replaces all query string parameter values with a user-specified value. The tool accepts URLs through stdin and systematically modifies query string parameters by substituting their original values with a replacement value provided by the user. This functionality allows security professionals to standardize query parameters across multiple URLs for testing purposes. The tool operates through a simple command structure where URLs are piped into qsreplace, and the replacement value is specified using the -v flag. All query string values in the input URLs are then uniformly replaced with the designated substitute value. This approach enables consistent parameter manipulation across large sets of URLs, making it useful for security testing scenarios where standardized input values are required for vulnerability assessment or penetration testing activities.