# PING












Returns `PONG` if no argument is provided, otherwise return a copy of the
argument as a bulk.
This command is useful for:
1. Testing whether a connection is still alive.
1. Verifying the server's ability to serve data - an error is returned when this isn't the case (e.g., during load from persistence or accessing a stale replica).
1. Measuring latency.

If the client is subscribed to a channel or a pattern, it will instead return a
multi-bulk with a "pong" in the first position and an empty bulk in the second
position, unless an argument is provided in which case it returns a copy
of the argument.

## Examples


PING

PING "hello world"


## Return information

{{< multitabs id="ping-return-info" 
    tab1="RESP2" 
    tab2="RESP3" >}}

Any of the following:
* [Simple string reply](../../develop/reference/protocol-spec#simple-strings): `PONG` when no argument is provided.
* [Bulk string reply](../../develop/reference/protocol-spec#bulk-strings): the provided argument.

-tab-sep-

Any of the following:
* [Simple string reply](../../develop/reference/protocol-spec#simple-strings): `PONG` when no argument is provided.
* [Bulk string reply](../../develop/reference/protocol-spec#bulk-strings): the provided argument.