Embedding endianness information within data and sending and receiving data with the embedded endianness information. Data may be contained in a data structure. To embed endianness information in a data structure, unused bits in a data structure are identified. A number of the unused bits are then selected based on the possible unpacking combinations of the data structure. The endian bit values are set to a pattern to indicate the endianness of the data structure. Data that has been packed by a transmitting module can be unpacked by a receiving module based on the detected endian bits. An algorithm may be used to determine which unused bits to select as the endian bits.