MMCX (micro-miniature coaxial) connectors are coaxial RF connectors similar to MCX but smaller. They conform to the European CECC 22000 specification. MMCX connectors are rated to 500 pairing cycles.

​

The connectors have a lock-snap mechanism allowing 360-degree rotation and usually have a 50-Ohm impedance. They offer broadband capability from DC to 6 GHz.

​

MMCX connectors are most commonly seen on Wi-Fi PCMCIA cards as antenna connectors or as connectors for external GPS antennas on small devices like PDAs or GPS receivers. They are also used by various brands of in-ear monitors to connect the cable to the individual earpieces. This allows for the cables to be replaced or swapped. They were developed in the 1990s.