JustLauncher vs PrismLauncher

PrismLauncher will not start Minecraft until you have bought it. That is a deliberate choice by its maintainers, and it is the main thing we differ on.

Download JustLauncher

Offline accounts: the real split

PrismLauncher does have offline profiles, but you can only create one after signing in to a Microsoft account that owns Minecraft. Offline mode there is built for playing a copy you already own without an internet connection, not for getting by without one.

How much that matters shows in the forks living around the project for the sole purpose of lifting the restriction. One describes itself as a “fork of Prism Launcher which aims to unblock the use of Offline Accounts, disabling the restriction of having a functional Online Account”. The Prism maintainers chose this deliberately; it is not an oversight.

In JustLauncher an offline account is made straight away, and a nickname is enough. A Microsoft account connects separately if you do own a licence.

The discussion in the PrismLauncher tracker

Feature by feature

Buy the game first

An offline profile in PrismLauncher can only be created after signing in to a Microsoft account that owns Minecraft. In JustLauncher a nickname is enough.

Play without a Mojang licenceJustLauncherYes, an offline account is made from a nicknamePrismLauncherOnly after signing in to an account that owns the game
Import instances from other launchersJustLauncherFinds them itself: ten launchers, including Prism, MultiMC and PolyMCPrismLauncherArchives in .zip and .mrpack (Modrinth, CurseForge, Technic, MultiMC) and FTB App instances. Auto-detection of other launchers is not documented
Rolling back a modpack updateJustLauncherSnapshot before the update, restore if it breaksPrismLauncherNot documented
Skins and capesJustLauncherBuilt in, capes as PNG up to 512 KBPrismLauncherNot documented
Playing togetherJustLauncherLobby by code, no server setupPrismLauncherNot documented
AppearanceJustLauncher3 themes and 5 accent coloursPrismLauncherCustom themes
Open sourceJustLauncherNoPrismLauncherYes, GPL-3.0
macOSJustLauncherVersion in developmentPrismLauncherAvailable

The same in both: Free, Modrinth and CurseForge inside the launcher, export to .mrpack and CurseForge, Windows and Linux.

“Not documented” means the feature is not described on that launcher's own site. That is not the same as it being absent.

Where Prism wins

PrismLauncher is free software under GPL-3.0 and a fork of MultiMC, which it is not endorsed by. You can read the code, build it yourself and satisfy yourself that the launcher does exactly what it claims.

JustLauncher is closed source. Updates arrive through a built-in updater, but you cannot read the code. If that settles it for you, it settles it for Prism. Saying so plainly beats pretending the line is not there.

Mods: catalogues and moving them

On mods the two are close: both install packs straight from Modrinth and CurseForge, with no dragging files into folders by hand.

They part ways on the move itself. JustLauncher picks up finished instances from PrismLauncher, and from MultiMC and PolyMC as well, along with mods, worlds and configs. An instance can also travel as a file: drop the modpack archive into the import window.

How to move your instances

PrismLauncher and MultiMC are trademarks of their respective owners and JustLauncher is not affiliated with them. This comparison was put together from PrismLauncher's own site and repository, September 2026.