Hot launches land in as little as 13 seconds thanks to a heavily optimized, ultra-lightweight architecture that stays out of your system's way — and every Modrinth and CurseForge mod lives in one search, synced through our secure backend.
Hot launch = relaunching an instance Vesper has already cached. First-time setup downloads assets and takes longer.
Hot launch
SinglePlayer · cached instance
Vesper strips the launcher down to what matters — then makes that part quick.
Every mod, modpack, shader, and plugin from Modrinth and CurseForge in a single search — powered by Vesper's backend databases, which keep the index current and filtered to your loader and game version.
A heavily optimized architecture with a deliberately small memory footprint. Vesper stays idle in the background instead of competing with the game for RAM and CPU, so your frames go where they belong.
Relaunching a cached instance can put you back in your server or single-player world in as little as 13 seconds. Assets stay verified on disk, so Vesper skips straight to spinning up the game.
Set up mods, tune your profile, and drop into the fight — without the launcher ever getting in the way.
Your PvP instance stays cached and verified between sessions. Hit Play, watch the 13-second hot launch tick down, and land back on the server while the lobby's still filling — no re-downloading, no re-validating, no dead time.
Watch a full install play out — search, resolve, download, launch. Click any step to jump to it.
Browse a library of skins, add one to your wardrobe, and apply it to any instance — with a live preview of how it will render in game.
Profiles and skin selections sync through Vesper's account services.
Home
Pick an instance and press Play — runtimes, libraries and assets are fetched for you.
Accounts
Microsoft sign-in for online play, or an offline profile to start immediately.
Per-instance tuning
Heap size and Java runtime per profile, with sensible defaults already set.
The client stays thin because the hard work happens upstream. Vesper relies on secure external databases and high-performance backend services to index both mod platforms, resolve compatibility, and keep your account and profiles in sync across machines — which is exactly why the desktop app can stay this small and this quick.
Unified mod index
Modrinth and CurseForge metadata, merged and kept current server-side.
Seamless mod syncing
Instances and mod sets follow you between machines.
Account services
Secure sign-in, profiles, and skin libraries.
Resolution off-device
Compatibility math runs server-side, not on your CPU.
An internet connection is required for search, syncing, and account features. Cached instances still hot launch once they're on disk.
Install the client, sign in, and your first instance is a few clicks away.
Every build ships with a published SHA-256 checksum. Vesper is in beta and the builds are not yet code-signed — on macOS right-click the app → Open, on Windows choose More info → Run anyway.
