Each of a plurality of documents is divided into samples. Small bit-strings are generated for selected samples from each of the documents and used to create a sketch for each document. Because the bit-strings are small (e.g., only one, two, or three bits in length), the generated sketches are smaller than the sketches generated using previous methods for generating sketches, and therefore use less storage space. The generated sketches are compared to determine documents that are near-duplicates of one another.