Efficient XML Interchange (EXI) is a data format used in the Internet of Things( IoT) for the compact binary representation of XML information. The EXI data format was proposed by the World Wide Web Consortium(W3C) and consists of the EXI header and the EXI body.
In developing the EXI data format, W3C emphasized that the data format should be efficient, flexible, interoperable, and have no major overhead. As a result, the EXI data format can be processed faster than text-based XML documents, and it requires low bandwidth for data transmission. The EXI header carries format information and options that are used for encoding. The EXI body contains an event sequence used to describe encoded documents.