Prism4Free

Contributors: Pancakes, DomHeadroom, LTSC recommender, InternetNinja and TheRedSpecial

PrismLauncher does not allow you to create an offline account without having a Mojang / Microsoft account. If you click the "Add Offline" button, you will be presented with this error.
Error - You must add a Microsoft or Mojang account that owns Minecraft before adding an offline account. If you lost your account, contact Microsoft for support.

It can be easily bypassed.

Please close PrismLauncher before starting. If it's open, please close it. You will need to (re)open it only in the end.

Please do not delete the "No profile (Xbox profile missing)" account, as doing so will trigger the above error.

Automatic Installation

Windows

Press the Windows key and choose any one of the following options:

Option 1: Search for CMD and Run as administrator.
Option 2: Search for Terminal and Run as administrator and then change it from Powershell to Command Prompt.

Then paste the following:

⎗
✓
echo {"accounts":[{"active":true,"entitlement":{"canPlayMinecraft":true,"ownsMinecraft":true},"profile":{"capes":[],"id":"0","name":"","skin":{"id":"","url":"","variant":""}},"type":"MSA","ygg":{"extra":{"clientToken":"0","userName":""},"iat":0,"token":"0"}}],"formatVersion":3} > "%appdata%/PrismLauncher/accounts.json"

Launch Prism Launcher, click on the top right button which displays "No profile (Xbox profile missing)" and you will notice a new offline profile has appeared.
Click on the Add Offline button, type in your username you want and Enjoy playing Minecraft without Mojang or Microsoft accounts, using PrismLauncher or even MultiMC and its forks.

Linux

Open the terminal and paste the following
If you are using the AppImage or the Native.

⎗

echo '{"accounts":[{"active":true,"entitlement":{"canPlayMinecraft":true,"ownsMinecraft":true},"profile":{"capes":[],"id":"0","name":"","skin":{"id":"","url":"","variant":""}},"type":"MSA","ygg":{"extra":{"clientToken":"0","userName":""},"iat":0,"token":"0"}}],"formatVersion":3}' > ~/.local/share/PrismLauncher/accounts.json

If you are using the Flatpak version.

⎗

echo '{"accounts":[{"active":true,"entitlement":{"canPlayMinecraft":true,"ownsMinecraft":true},"profile":{"capes":[],"id":"0","name":"","skin":{"id":"","url":"","variant":""}},"type":"MSA","ygg":{"extra":{"clientToken":"0","userName":""},"iat":0,"token":"0"}}],"formatVersion":3}' > ~/.var/app/org.prismlauncher.PrismLauncher/data/PrismLauncher/accounts.json

Launch Prism Launcher, click on the top right button which displays "No profile (Xbox profile missing)" and you will notice a new offline profile has appeared.
Click on the Add Offline button, type in your username you want and Enjoy playing Minecraft without Mojang or Microsoft accounts, using PrismLauncher or even MultiMC and its forks.

MacOS

⎗
✓
echo '{"accounts":[{"active":true,"entitlement":{"canPlayMinecraft":true,"ownsMinecraft":true},"profile":{"capes":[],"id":"0","name":"","skin":{"id":"","url":"","variant":""}},"type":"MSA","ygg":{"extra":{"clientToken":"0","userName":""},"iat":0,"token":"0"}}],"formatVersion":3}' > ~/Library/Application\ Support/PrismLauncher/accounts.json

Manual Installation

Windows

Go to PrismLauncher's directory by pressing Win + R and then pasting %AppData%/PrismLauncher.
Choose any one of the following options:

Option 1: Download the accounts.json file and move it to the folder. (Hint: click on accounts.json to download the file (⌒‿⌒) )

Option 2: Create a new file named accounts.json in the PrismLauncher folder and open it with your preferred text editor. Paste the following line into the file and save it.:

⎗
✓
{
    "accounts": [
        {
            "active": true,
            "entitlement": {
                "canPlayMinecraft": true,
                "ownsMinecraft": true
            },
            "profile": {
                "capes": [
                ],
                "id": "0",
                "name": "",
                "skin": {
                    "id": "",
                    "url": "",
                    "variant": ""
                }
            },
            "type": "MSA",
            "ygg": {
                "extra": {
                    "clientToken": "0",
                    "userName": ""
                },
                "iat": 0,
                "token": "0"
            }
        }
    ],
    "formatVersion": 3
}

accounts.json is created
accounts.json on NotePad

Launch Prism Launcher, click on the top right button which displays "No profile (Xbox profile missing)" and you will notice a new offline profile has appeared.
Click on the Add Offline button, type in your username you want and Enjoy playing Minecraft without Mojang or Microsoft accounts, using PrismLauncher or even MultiMC and its forks.

Linux

Make sure to check show hidden files inside your file manager settings

Go to PrismLauncher's directory
~/.local/share/PrismLauncher if you are using the AppImage or the Native or
~/.var/app/org.prismlauncher.PrismLauncher/data/PrismLauncher if you are using the Flatpak version.
Choose any one of the following options:

Option 1: Download the accounts.json file and move it to the folder. (Hint: click on accounts.json to download the file (⌒‿⌒) )

Option 2: Create a new file named accounts.json in the PrismLauncher folder and open it with your preferred text editor. Paste the following line into the file and save it:

⎗
✓
{
    "accounts": [
        {
            "active": true,
            "entitlement": {
                "canPlayMinecraft": true,
                "ownsMinecraft": true
            },
            "profile": {
                "capes": [
                ],
                "id": "0",
                "name": "",
                "skin": {
                    "id": "",
                    "url": "",
                    "variant": ""
                }
            },
            "type": "MSA",
            "ygg": {
                "extra": {
                    "clientToken": "0",
                    "userName": ""
                },
                "iat": 0,
                "token": "0"
            }
        }
    ],
    "formatVersion": 3
}

accounts.json is created
accounts.json on Kate

Launch Prism Launcher, click on the top right button which displays "No profile (Xbox profile missing)" and you will notice a new offline profile has appeared.
Click on the Add Offline button, type in your username you want and Enjoy playing Minecraft without Mojang or Microsoft accounts, using PrismLauncher or even MultiMC and its forks.

MacOS

Requires screenshots, the automatic version has been provided by InternetNinja and tested by TheRedSpecial