pinger

Pinger can refer to several concepts in technology and science.

In computer networking, a pinger is a program or utility that sends Internet Control Message Protocol (ICMP) echo requests to a host to determine reachability and measure latency. The responses are ICMP echo replies. Pingers report metrics such as round-trip time and packet loss and are used for diagnostics, monitoring, and troubleshooting networks. Common examples include the ping command on various operating systems.

In underwater acoustics, a pinger is an active acoustic beacon that emits short, periodic sonar pings. These beacons enable tracking, ranging, or identification of submerged assets such as moored instruments, autonomous underwater vehicles, or tags attached to wildlife. Hydrophone arrays detect the pings and derive location or timing information.

In branding, Pinger is the name of a technology company known for consumer mobile messaging services and apps. The company historically offered free text messaging and voice over data services and developed platforms that allowed users to send SMS‑like messages, often bypassing traditional carrier charges.