How Kepler Works: Kepler vs. Standard Launcher

• Out-of-the-box profile & calibration: Provides a ready-to-use profile and runs a 2‑3 minute calibration across 3-4 candidate profiles to pick the winning profile for your hardware.
• Automatic Java & memory tuning: Selects the right Java version from Mojang's version manifest and recommends RAM (heap) and JVM flag presets based on system memory and mod count.
• Modrinth-based mod management: Searches Modrinth directly, resolves dependencies automatically, installs mods with SHA-1 verification, and checks for updates.
• Backups & sharing: Backs up your worlds or full profile as a .zip archive, and imports/exports .mrpack modpacks and compact KEPLER1: share codes.
• In-game modules & crash analysis: Provides 4 Fabric in-game HUD/utility modules and a crash report analyzer that masks personal paths and usernames.

• Does not redistribute game files: Does not host modified game binaries; game and Java files come from official sources, and mods are downloaded directly from Modrinth.
• Does not promise fixed speed or FPS numbers: Performance depends on your hardware and mod choices; Kepler does not claim unverified FPS multipliers or speed guarantees.
• Does not grant immunity from server rules: Provides only informational HUD widgets and profile tools; it never guarantees ban safety, and multiplayer server rules always apply.
• Does not collect telemetry or show ads: Does not track usage in the background, display advertisements, or sell paid tiers or donor perks.
• Never sees your Microsoft password: Sign-in runs through the official PKCE OAuth2 flow in your system browser, storing refresh tokens in the OS keyring.

Create clean or modded (Fabric, Quilt) isolated profiles, duplicate existing profiles with their worlds, delete profiles safely, assign per-profile themes, and import profiles with worlds from existing launchers on your computer.

Search the Modrinth catalog directly inside the launcher, plan required dependencies automatically, install files with SHA-1 verification, and check installed mods for version updates.

Create atomic one-click .zip backups of your worlds or entire profile directory, list and manage saved backups, and restore previous states with an automatic pre-restore safety backup.

Export your profile via a compact KEPLER1: share code or as a Modrinth .mrpack archive, and import .mrpack and compatible .zip packages with path-traversal protection and SHA-1 checks.

Reads system RAM and CPU core count to calculate heap allocation recommendations, applying Low-end, Balanced, or High-performance JVM launch flag presets suited to your hardware.

Streamlines pre-launch setup with a lightweight Tauri v2 + Rust desktop UI, automatic Java selection, and ready profile configuration; records session performance samples to suggest tuning advice.

Open your profile directory and screenshots folder directly in your operating system's file manager with one click, and position in-game HUD indicators anywhere on your screen.

Inspects exit codes and console output when the game closes unexpectedly to identify likely mod conflicts, lets you disable suspected mods from the UI, and masks usernames and file paths in crash reports.

Launcher settings, server lists, and profile data are stored strictly locally on your computer (with atomic JSON storage and .bak recovery); no background usage telemetry is sent.

Neither the desktop launcher interface nor the website contains ad banners, sponsored mod placements, or promotional pop-ups.

Kepler is completely free with open access to all features; there are no paid subscriptions, paid cosmetics, or donor-only privileges.

Monitor saved multiplayer servers for latency and player count via Server List Ping (SLP), and sign in with official PKCE OAuth2 Microsoft authentication or use an offline account for singleplayer.