Overview

Refract brings modpack sources including Modrinth, CurseForge, and FTB into one launcher. Each pack gets a clean instance, with its own mods, resource packs, worlds, settings, and launch options. That separation is useful for players who switch among distinct setups and want to avoid files or settings bleeding between them.

Players can import existing libraries without mixing files or breaking saves. Refract preserves worlds during updates, supports updating individual mods in place, and can install mod dependencies. These tools make it a compelling fit for ongoing pack maintenance, though its documented strengths are concentrated on managing modded Minecraft rather than broader game-launching needs.

Compatible content can be browsed inside the launcher, and customization includes themes, accent colors, sidebar layouts, Java versions, memory limits, and launch behavior. The project uses Tauri and Rust for its native shell and is developed in public. Discord supports player help and project discussion; GitHub is used for bug reports, code contributions, and change proposals, with a separate space for longer questions and ideas.

Key features

Isolated instances: Separate mods, resource packs, worlds, settings, and launch options for each pack. This is the core advantage for players maintaining multiple configurations.
Import and source support: Bring in existing libraries and use packs from Modrinth, CurseForge, and FTB. Importing is designed to preserve separation and saves.
In-launcher upkeep: Browse compatible content, install dependencies, and update individual mods. World preservation during updates helps protect ongoing play.
Runtime controls: Manage Java versions and memory limits, alongside themes, layouts, and launch behavior. These options suit players who want to tune how each setup runs.
Automatic updates: Refract includes automatic updates, reducing the need to manage launcher updates manually.

Pricing

Refract is free software under the GNU GPL v3.0, and a free plan is available. The Free software plan has custom pricing; no paid tier, seat count, quota, or trial terms are given. Its open license and public development make it a clear option for players who value free software as well as a free-to-use launcher.

Platforms

Refract runs on Windows, macOS, and Linux. That covers the major desktop platforms, but it is not an option for players seeking a mobile launcher.

Who it's for

Choose Refract if you manage several modpacks, want their worlds and settings kept apart, or prefer to discover and maintain compatible content from the launcher. Its import, dependency, and per-mod update features are especially relevant to players who regularly adjust existing packs. Look elsewhere if you need a mobile option or a launcher whose appeal rests on capabilities beyond the modpack and instance tools described here.

Pros and cons

Pro: Instance isolation covers worlds, settings, mods, resource packs, and launch options, helping keep different packs distinct.
Pro: Imports are designed not to mix files or break saves, and worlds are preserved during updates.
Pro: Mod discovery, dependency installation, and individual mod updates are integrated into the launcher.
Pro: Free software licensing and public development give users a clear view of the project’s open approach.
Con: Refract is limited to Windows, macOS, and Linux, so mobile players need another option.
Con: The documented feature set focuses on modpack management, making it a less natural fit for players who do not need those tools.

Alternatives

Prism Launcher is a free, open-source alternative for Linux, macOS, and Windows, with a listed price of $0.
LabyMod is worth considering if you want a launcher spanning desktop and mobile platforms. Its free LabyMod 4 plan covers Minecraft Java Edition on Windows, macOS, and Linux, with 20+ versions; Laby+ has custom pricing and is billed one-time.
X Minecraft Launcher is another free, open-source launcher for Linux, macOS, and Windows, priced at no cost.
ATLauncher is a free, open-source desktop alternative at no cost. It requires a paid Minecraft account to use the launcher and play modpacks.
Thendrask Launcher has a free download and use option, with no required subscription, plus an End Crystal plan at 3.00 USD per month.
Cactus MC Launcher offers a free-forever, open-source desktop build with no ads and no premium tier.
GDLauncher is a free desktop alternative with no premium tier and no overlay.
Minecraft Launcher is available free across desktop and mobile platforms, though access to games requires ownership or a time-limited demo.
Minecraft Launchers collects more options to compare.

Verdict

Refract is a strong choice for desktop players who want a free, open-source launcher centered on isolated modpack instances and practical upkeep. Its import protections, world-preserving updates, and integrated mod tools make it particularly well suited to managing several packs. Choose another launcher if mobile support or a different emphasis matters more than Refract’s instance-management approach.

	Cosmic Client	Refract
Free plan		Yes
Free trial	No
Paid from		Free
Platforms	Windows	Windows, macOS, Linux
Free plan	Yes	Yes
Desktop OS support	windows
Separate instances		Yes
Modpack import		both
Mod loader support		multiple
Java runtime management		Yes
Built-in modpack catalog		Yes
Automatic updates		Yes

Cosmic Client vs Refract

Cosmic Client

Refract