About
The payload is the part of transmitted data that is the actual intended message or packet.
The payload excludes any headers (ie metadata) used for delivery or processing purpose.
The term is borrowed from transportation, where payload refers to the part of the load that pays for transportation.
The most common usage of the term is in the context of packet and message protocols, to differentiate the protocol overhead from the actual data.
Length and Max Size
- The payload is the data that is carried on behalf of an application.
- It is of variable length,
- up to a maximum that is set by:
- the network protocol
- the interface on the route (software or hardware) via the MTU
Example
For example, a JSON web service response might be:
{
"data":{
"message":"Hello, world!"
}
}
where:
- The string Hello, world! is the payload,
- The rest is protocol overhead.