A data compression device includes a processor configured to extract delimiter characters and character strings from compression target data. The character strings each are sandwiched between two of the delimiter characters in the compression target data. The processor is configured to generate first data by arranging the delimiter characters to allow an order in which the delimiter characters occur in the compression target data to be identified. The processor is configured to generate second data by arranging the character strings for each type of combination of two of the delimiter characters, which sandwich each of the character strings in the compression target data, to allow an order in which the character strings occur in the compression target data to be identified. The processor is configured to perform compression on the first data and the second data. The processor is configured to output a result of the compression.