F3 is used by holding down shift while using any block with an inventory tool like shovel or sword. This command allows you to quickly select items from your inventory without opening them with an inventory tool like shovel or sword every time you need one item like blocks from chests or items from dispensers The following are all F3 commands in Minecraft MinecraftEcho /minecraftEcho Text | This command lets you type messages that will show up at both players (and mob) - at once!