Filling out document forms distributed by email or hosted on the Web is still problematic and usually requires a printer and scanner. Users commonly download and print forms, fill them out by hand, scan and email them. Even if the document is form-enabled (PDFs with FDF information), to read the file users still have to launch a separate application which may not be available, especially on mobile devices. FormCracker simplifies this process by providing an interactive, fully web-based document viewer that lets users complete forms online. Document pages are rendered as images and presented in a simple HTML-based viewer. When a user clicks in a form-field, FormCracker identifies the correct form-field type using lightweight image processing and heuristics based on nearby text. Users can then seamlessly enter data in form-fields such as text boxes, check boxes, radio buttons, multiple text lines, and multiple single-box characters. FormCracker also provides useful auto-complete feature...