LEVIATHAN LAUNCHER

Everything before you press Play.

Manage versions, loaders, runtimes, content, migration and diagnostics from one launcher designed to make complex Minecraft setups easier to understand.

Download availability →Explore features

Leviathan Launcher

Ready when you are.

Conceptual product preview

SELECTED INSTANCEMinecraft Java

1.21 · Fabric · 42 mods

RUNTIMEJava 21

MEMORY4 GB

HEALTHGood

Migration readyPreview + backup first

System awareConservative recommendations

Features Migration System tuning Diagnostics Download

CORE LAUNCHER

Power without the clutter.

The launcher should expose the details advanced players need while still making everyday launch, install and repair tasks feel straightforward.

Instances

Keep versions, loaders, mods, settings and saves isolated so one setup does not break another.

Content library

Organize mods, modpacks, resource packs and shaders around compatibility instead of folders alone.

Runtime management

Detect, recommend and provision appropriate Java runtimes for different Minecraft versions and workloads.

Account flow

Use supported Microsoft and Minecraft authentication while keeping credentials and tokens out of unsafe surfaces.

Repair tools

Detect missing, corrupt or mismatched files and explain what can be repaired safely.

Updates

Keep launcher changes visible through versions, release notes, checksums and staged release channels.

MIGRATION

Move in without rebuilding everything.

Leviathan is being designed to scan compatible data from other launchers, show what can be imported, resolve conflicts before changes are made and create a backup first.

01Preview firstSee worlds, mods, packs, settings and conflicts before import.

02Backup firstCreate a rollback point before anything is moved.

03Conflict handlingChoose which compatible settings and files win when duplicates exist.

Import preview9 categories found

✓

Worlds7 ready

Ready

✓

Mods & packs46 compatible

Ready

Settings2 conflicts

Review

✓

Screenshots118 files

Ready

System recommendationBalanced

Java runtimeVersion-aware recommendation

Java 21

MemoryConservative target based on workload

4 GB

GraphicsDetected GPU and compatibility profile

Good

SYSTEM AWARE

Smarter defaults for your PC.

Recommendations should account for total memory, CPU, GPU, operating system, Minecraft version, loader and modpack size while remaining transparent and user-overridable.

DIAGNOSTICS

Errors with context.

Leviathan error codes are intended to connect launcher failures to original errors, likely causes, remediation, known issues and support records without hiding the underlying details.

Crash diagnosticsCorrelation IDs, exit codes and privacy-safe bundles

Building

Download diagnosticsHTTP status, source, retries, size and checksum context

Building

Known issue linkingConnect recurring failures to fixes and release versions

Planned

Help Center integrationOpen the right article from the launcher

Planned

Follow launcher development.

Public downloads will appear only when the launcher and release pipeline are ready for wider testing.

View GitHub Join Discord