Systems and methods display input suggestions on web pages having an input field for receiving a specific type of user input. A module stored on a user device is remote from a database containing the input suggestions. The module detects the presence of any input fields of a specific type in a web page. For each detected input field of the specific type, the module generates a combo box that is displayed so as to cover and visually replace the input field. The combo boxes display input suggestions contained in the database. The database can be updated to add or remove input suggestions for particular websites determined to be valid or invalid at those websites. Analysis of the validity of the input suggestions can be based on page analyses sent from the module and performed before and after any submission of an input suggestion.