This is a Fabric mod. For the Forge version, go here.
A mod for displaying each player's ping in the player list as a number, with various configuration options.
This is a client side mod. The server doesn't need to have it installed. It can even be used when playing on vanilla servers.
Configuration
See https://github.com/vladmarica/better-ping-display-fabric#configuration for an explanation of what the various config options do.