Signals are very small, transient messages that represent momentary snippets of information that do not require extensive tracking and backup, as each one will be rapidly replaced by the next signal.

A signal may be part of a high-volume stream of payloads intended to inform or instruct an application without including information that would be directly reflected in an application UI. Examples of signals include rideshare driver latitude and longitude measurements, a command to switch on a chat app typing indicator, and more.

By default, signals are limited to a message payload size of 64 bytes. This limit applies only to the request body and not to the URI or headers. If you require a larger payload size, contact PubNub Support at