1. A computer system for classifying a uniform resource locator (URL), the computer system comprising: A processor set; and A non-transitory computer readable storage medium; Wherein: The processor set is structured, located, connected, and/or programmed to run program instructions stored on the non-transitory computer readable storage medium; and The program instructions include: First program instructions programmed to configure a bloom filter to identify a pre-determined set of URL categories; Second program instructions programmed to program the bloom filter with a set of URLs, each URL in the set of URLs belonging to a respectively corresponding URL category of the pre-determined URL categories; Third program instructions programmed to extract a second URL in-line with a data transmission from a network packet stream; Fourth program instructions programmed to determine a set of hash strides for the second URL; Fifth program instructions programmed to query the bloom filter with each hash stride of the set of hash strides, the querying being performed in a data plane; Sixth program instructions programmed to identify a sub-set of categories from the pre-determined set of URL categories, the sub-set of categories being URL categories that correspond to the second URL; Seventh program instructions programmed to determine a first URL category based, at least in part, on a programmable mapping table that defines the sub-set of URL categories as the first URL category; and Eighth program instructions programmed to report the first URL category as a classification of the second URL in human-readable form.