Searching is a necessary tool for managing and navigating the massive amounts of data available in today's information age. While new searching methods have become increasingly popular and reliable in recent years, such as image-based searching, these methods may be more limited than text-based means in that they do not allow generic user input. Sketch-based searching is a method that allows users to draw generic search queries and return similar drawn images, giving more user control over their search content. In this paper, we present SketchSeeker, a system for indexing and searching across a large number of sketches quickly based on their similarity. SketchSeeker introduces a technique for indexing sketches in extremely compressed representations, which allows for fast, accurate retrieval augmented with a multilevel ranking subsystem. SketchSeeker was tested on a large set of sketches against existing sketch similarity metrics, and it shows significant improvements in terms of storage requirements, speed, and accuracy.