A system for testing multiple language versions of a browser-based application. A host language Hypertext Transfer Protocol (HTTP) request issued by a host language browser is received. The host language HTTP request is configured to be sent to a host server address. The host language HTTP request comprises parameter strings in a host language. A target language HTTP request is generated by replacing each host parameter string of at least one host parameter string of the parameter strings in the received HTTP request with a respective target parameter string associated with a target language that differs from the host language. The generated target language HTTP request is configured to be sent to a target server address associated with and different from the host server address.