Computer programs and computer-implemented methods implement techniques for generating input fields (including form fields, sketch fields, text fields, and the like) in electronic documents. These include representing an electronic document to a user, receiving user input specifying a location in the electronic document, identifying one or more graphical elements in the electronic document, and generating an input field in the electronic document at the specified location based at least in part on the identified graphical elements. The techniques can also include receiving user input entering information into the generated input field and storing the generated input field.