OBEX is an acronym that stands for OBject EXchange, mostly used in the communications technology field as a communications protocol. Because the Infrared Data Association maintains OBEX, it is also known as IrOBEX or Infrared OBEX.

OBEX is primarily designed for swapping binary objects between particular devices. This means that an OBEX is designed to function like http, as it allows the user to connect to a server in much the same way. Once connected to a server, the user can either make a request or provide objects to OBEX. Some of the objects that the user can chose to provide to OBEX include files, pictures, calendar entries and business cards.

OBEX is usually associated with and optimized for ad-hoc wireless links. There was a time, however, when OBEX was reserved for only infrared connections. Today, OBEX can run on most transport devices, TCP/IP, and Bluetooth®. Bluetooth® is a form of industry specification used for wireless personal area networks (PANs).

OBEX is also built into most modern communications devices. Personal digital assistants (PDAs), such as the Palm Pilot and others, were the first communication devices to be run using OBEX. OBEX can also be found in cell phones, especially those made from brand companies like Sony-Ericsson and Siemens. HP CapShare and JetSend Scanners, as well as Microsoft Windows2000, are also OBEX supported products.

OBEX is often referred to as a session protocol or a binary http protocol. With its binary transmissions, OBEX utilizes a binary-formatted length value, which is also called Headers. The binary transmission allows for the exchange of information in reference to a particular request or an object.

With session support, OBEX can make a single transport connection branch off into several other related operations. In other words, if a transaction has been closed, the use of OBEX can resume the transaction with all information remaining untouched.