A method includes accessing a page of Web application that includes an interactive form having at least one field for entry of data, the interactive form rendered by the Web application based on code for the interactive form. The method also includes extracting input validation code from the code, the input validation code including at least one constraint on data entered into the at least one field. The method additionally includes extracting the at least one constraint based on an analysis of the input validation code and solving, for the at least one field, for a string value based at least on the at least one constraint for the at least one field. The also includes automatically entering, into the at least one field, the string value. The method additionally includes automatically submitting the interactive form, including the string value entered into the at least one field.