Various embodiments are directed to systems and methods for compressing digital works, such as books, magazines and similar works. Compressing a digital work may comprise finding an entry for a first string from the digital work in a compression dictionary and replacing a string value of the first string from the digital work with a first string reference associated with the first string at the entry for the first string. The compression dictionary may be generated, for example, from digital works associated with a user or user device that requested the digital work. Also, in some embodiments, the digital work itself may be used as a compression dictionary.