Tools
Minecraft: Java Edition
Minecraft profile
Look up a Minecraft player: their skin in 3D, UUID, head commands and Mojang API links.
Their skin in 3D
Drag to turn it round. Click to swing, crouch, put on an elytra and fly, or take the outer layer off.
Head commands
The give command for their player head, written for the version you play, from 1.8 to the latest.
Names and skins seen
Mojang no longer shares name history, so this site keeps its own record of the names and skins it sees each player use.