Abstract: Techniques for auto-categorization data may be provided. For example, a computing service may be implemented to analyze data sets. A first data set may include data strings pre-categorized in various groups. For a group, the computing service may generate a relevant data string representative of the group by considering how relevant that data string may be to the group and to other groups. A second data set may include an uncategorized data string. The computing service may match the uncategorized data string to the relevant data string and, accordingly, may categorize the uncategorized data string as belonging to the group.