Abstract: A text completion system is described herein that completes text at a tag and/or attribute level based on a syntactic understanding of software program code. The system includes sets of elements and associated attribute-value pairs that represent interesting, common, and repeated patterns. As a user is editing a web page or other document in an editing tool that implements the system, the user can retrieve, select, and insert these patterns using simple commands. The system receives a selected pattern from the user, and inserts target text associated with the pattern. In addition, users can fill in instance-specific data within the larger pattern to allow a single pattern to cover several common and closely related scenarios. Thus, the text completion system increases user productivity by providing more intelligent text completion through a syntactic understanding of the language in which a document is written.