An open-source launcher for Minecraft: Java Edition
Halcyo sets up Minecraft, Fabric and your mods in one click. No ads, no tracking, and nothing about you to sell.
Free and open source under the GPL-3.0 license.
Everything before you press Play
The launcher handles the setup, so you only choose a version and play.
Fabric, set up for you
Fabric Loader and Fabric API are installed and kept up to date before every launch.
Performance mods
Sodium, Lithium, ImmediatelyFast and Iris, each one can be turned off.
Your own mods
Add the mods you want and the launcher will keep them updated.
Your own instance
Every setup gets its own folder, mods and memory, kept apart from your other launchers.
How Halcyo compares
Lunar, Badlion and Dawn are free, and their own privacy policies explain how your data pays for it. Halcyo has no servers, no ads and nothing to sell.
| Feature | Halcyo | Lunarand Badlion | Dawnformerly Feather |
|---|---|---|---|
| Open source | Yes | No | No |
| Ads in the launcher | No | Yes1 | Yes2 |
| Shares your data with advertisers | No | Yes1 | Yes2 |
| Data “sold” or passed to data brokers | No | Yes1 | No2 |
| Tracking on by default, without asking | No | Yes3 | Yes2 |
| Reads your Discord status for ads | No | Yes1 | No2 |
- 1.Moonsworth privacy policy for Lunar Client and Badlion Client, last updated September 22, 2025. Since August 13, 2024 it has disclosed IP address, Unified ID, zip code, internet activity and a hashed email address for targeted advertising, which “may also be referred to as the ‘sale’ or ‘sharing’ of your Personal Information”. Advertisers “may include entities known as ‘Data Brokers’”. It may collect your Discord status (games, music, apps) to show you ads, integrates Google Analytics, may send interaction data while you are not using the app, and may keep data for up to 5 years or longer. Read the policy
- 2.Dawn privacy policy (InPvP Inc., successor to Feather Client), last updated August 9, 2026. It states that it does not sell your data and does not track activity outside the launcher. The launcher displays ads, data is shared with its advertising partners, and a telemetry report is sent every time you launch Minecraft, without a confirmation prompt. Read the policy
- 3.Lunar Client “Do Not Sell or Share” page, last updated August 23, 2026: the Analytics and Optimized Ads settings “are enabled by default”, so you have to find them in the launcher settings and turn them off yourself. Read the policy
- Based on each company's own published policies, checked September 19, 2026.
The fine print, in their own words
Quoted straight from Lunar's and Dawn's own policies. We didn't change a word, we just wrote back.
“For efficiency’s sake, information about your interactions may be transmitted to our servers while you are not using the Services.”
Lunar Client privacy policy Halcyo has no servers to send anything to, whether it's open or closed.
“We may also collect information you make available in your Discord status, including information regarding what games you are playing, music or media you are accessing, or what apps you are using for the purpose of sending you advertisements within our Services.”
Lunar Client privacy policy Halcyo has no idea what you're listening to. Enjoy the song.
“We may store data for up to 5 years or longer if there is a valid business purpose or if we are legally required to do so.”
Lunar Client privacy policy Halcyo stores your data for zero years, on zero servers.
“If you would like to opt-out from everything, switch on Disable Amazon Publisher Audiences and switch off Customize your experience.”
Lunar Client “Do Not Sell or Share” page Halcyo has no privacy toggles, because there is nothing to opt out of.
“When you use the voice-chat feature of the Services, we process and collect audio information, which naturally includes any information you broadcast over the voice-chat feature.”
Lunar Client privacy policy Halcyo never hears you. Not even after you lose a clutch.
“Every time you launch Minecraft through the Dawn launcher, the launcher sends a short report to InPvP immediately, without a further confirmation prompt.”
Dawn privacy policy When you launch Minecraft with Halcyo, Minecraft launches. That's the whole report.
Play fair
Halcyo is a launcher, not a cheat client. There are no cheats built into it in any way, and there never will be.
No cheats, in any form
Halcyo has no cheats, hacks or hidden features built in, and never gives you an advantage over other players.
Nothing leaves your computer
There is no Halcyo account, no Halcyo server and no telemetry. The launcher has nowhere to send anything, and nothing to sell.
Mods come from their authors
Every mod is an unmodified file from Modrinth, under its author's license. Nothing is changed or added to them.