Abstract: A document checking system is presented that provides an asynchronous scan of a document for errors and presents a rich user interface to the user that provides information about the error and how to fix it. While the user is accessing the document, the document checking system scans the document to identify one or more violations of a set of rules. The system locates a context within the document for each identified rule violation and determines one or more steps for remedying each rule violation. The system displays a report that includes the identified rule violations along with detailed information about the context of each rule violation and how to fix it.