Play Multiplayer LAN with a Single Minecraft Account on Java Edition. Updated to support Microsoft Account!

With the recent update of the Minecraft Java Edition, the client now logs in and checks the profile each time it runs. It does this when the launcher runs, and also when the Minecraft game client is launched. As such you can no longer simple edit the launcher_profiles.json and change the profile name in order to play multiplayer LAN with a single Minecraft account.

Why multiplayer LAN with a Single Minecraft Account?

You will need a valid license If you want to play online and have the full experience of Minecraft. There’s no way around this. All Minecraft servers out in the world requires a valid and authenticated account.

However, if all you want is to play multiplayer on a local Minecraft server completely offline, you can do this without having a full Minecraft license running on each computer running Minecraft.

Running a local Minecraft server

This isn’t a complete guide on how to run a local server. To do so, you can simple just follow this simple guide here to download and run the Minecraft Server for Java Edition. A more detailed guide can be found here. I’ve also share a guide on how to automatically update the Minecraft Server as the game client and server gets updated quite often.

In the directory where you run the server.jar file, you will find the server.properties file. There are a bunch of properties that you can change as you like. But there is one properties that needs to be updated so that you can play multiplayer LAN on a single Minecraft account. Search for “online-mode” and change the value to “false”.

This will force the server NOT check if the players that are logged in are valid and authenticated users. Note that this is not recommended if your server is exposed to the Internet. So, only do this if your server is completely safe within the LAN network of your home.

Changing the Minecraft profile name

The main thing that you want to be able to do is to simply change the profile name of the player on the Minecraft launcher/client. The profile name is what the Server uses to determine the different players in the LAN game.

So the trick is to simply force the Launcher to run Minecraft in offline mode. The following would be the steps to take to do so.

Updated 21 Dec 2022: Includes instructions if you’ve migrated to Microsoft Account

1. The first time you run Minecraft, you will need to log in with your Minecraft account. Quit the launcher after you have logged in. If you’ve done so already, just skip to step 2.
   If you are using the newer Microsoft’s Account, I have noticed that the Minecraft Launcher will disable the login after a few days and will force you to re-login again. So, always start the launcher with the Wifi or network on first. Otherwise, it will start off in a “Play Demo” mode instead of “Play Offline” when started without Internet access.
2. Disconnect your computer from the Internet by turning off Wifi or unplugging the network cable.
3. Before running the Minecraft Java Edition launcher without access to the Internet, you need to first change the Minecraft profile name on the computer. It is now stored in the launcher_accounts.json file with the latest update of the Minecraft launcher. On macOS, this can be found at ~/Library/Application Support/minecraft, on Windows, %APPDATA%\.minecraft

4. Open the launcher_accounts.json file. You will easily find the profile name in the file. Edit the profile name as you like.

5. Launch Minecraft still without access to the Internet and you will see that the Launcher will now run the game in offline mode. When you run the game, the profile name should now reflect the one you have edited.

6. Click on Play Offline while the Internet is still offline! Wait for the game to load first before turning you Wifi back on.
7. After the game runs, you can now turn on Wifi or reconnect the network again so that you can now find and connect to the local server.

And that’s it! You can now again enjoy playing multiplayer LAN games with just a single Minecraft account.

Automated script to change the profile name!

As you can see from the steps above, it is quite a few things you need to do. Fret not, here’s a script file which you can use to automate Step 1 till 5 so you don’t have to manually do it every time. Do note that this script is for macOS. But I think can script an equivalent one for Windows

You can just download the sample script file here from my dropbox, or simple create it yourself with the example below.

#!/usr/bin/env bash

networksetup -setairportpower en0 on
open --wait-apps /Applications/Minecraft.app

echo "### Changing profile name ###"
sed -i '' 's/ExistingProfileName/NewProfileName/g' ~/Library/Application\ Support/minecraft/launcher_accounts.json

networksetup -setairportpower en0 off

open /Applications/Minecraft.app

As you can see, I made sure the network is on and off at the appropriate times. The script also waits until the Minecraft launcher is quit the first time before continuing to replace the profile name in the launcher_accounts.json file. After which, it would turn off Wifi and launch the Minecraft Launcher again, this time to force it to run in offline mode.

This leaves you to then start the game and then turn back the Wifi on manually. Hope this helps makes it easier for you to do this every time you play a multiplayer LAN game!

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