What Grim Anticheat works with.
| Platform | Java Edition |
|---|---|
| Loaders | Bukkit, Paper, Purpur, Spigot, Folia |
| Minecraft versions | 1.8, 1.12.2, 1.16.5, 1.18.2, 1.19.4, 1.20.1, 1.20.6, 1.21, 1.21.5, 1.21.8, 1.21.11, 26.1, 26.2 |
Grim Anticheat is an open source plugin that watches player movement and combat on your server and flags the physically impossible. It rebuilds a 1:1 model of what each connected client can legally do, frame by frame, then compares that against what the client actually reports. When the two disagree past a threshold, Grim logs it, alerts staff, or punishes automatically depending on how you configure it.
What a minecraft anticheat plugin like Grim actually does
Grim runs fully asynchronously off the main server thread, so it can check hundreds of players without dragging down tick rate on its own. It keeps a per player replica of the nearby world, built from the same chunk and block change packets the client receives, so it can verify movement against blocks, water, cobwebs, boats, and other entities exactly as that player's client sees them. Version differences are accounted for too: a 1.8 client and a 26.2 client see different hitboxes on the same glass pane, and Grim tracks both correctly, including through ViaVersion when a proxy bridges old and new clients.
Supported server software and versions
- Paper, Spigot, Purpur, Bukkit, and Folia, from a single Bukkit family download
- A separate Fabric build for Fabric server environments
- Minecraft versions 1.8 through 26.2 on the Bukkit family builds
- Fabric builds cover 1.16.1 through 26.2
- Java 17 or newer is required to run the plugin
If your setup runs a Velocity or BungeeCord proxy, install ViaVersion only on the backend server where Grim runs, never on the proxy itself. Geyser and Floodgate players are exempt from movement checks by default to avoid false positives from Bedrock input translation, so Floodgate needs to be installed on the same backend server for that exemption to work.
Setup and configuration
Installing the jar is the fast part. Getting real value out of Grim means going through the config afterward: adjusting which checks are active, setting punishment thresholds, wiring up Discord webhook alerts for staff, and deciding what gets an automatic ban versus a flag for manual review. Treat the install guide for Paper and Spigot as the starting point, then work through Grim's own wiki for check-by-check tuning.
How to install Grim Anticheat on your Minecraft server
Frequently asked questions
Questions about Grim Anticheat.
5 questions
Does Grim anticheat work with Paper servers?
Yes. Grim ships builds for Paper, Spigot, Purpur, Bukkit, and Folia from a single download. Pick your server software and Minecraft version on the Modrinth download page, drop the jar into the plugins folder, and restart. All five server types share the same feature set and configuration files.
Is Grim anticheat free?
Yes. Grim is released under the GNU General Public License, so the plugin, its source code, and every update are free to download and self-host. There is no paid tier or subscription required to run the current 2.0 feature set.
How do I set up Grim anticheat on my server?
Download the jar for your server software from Modrinth, install it in your plugins folder, and restart the server. Default settings work out of the box, but tuning checks, punishments, and Discord webhook alerts to fit your player base takes real config work. The GitHub wiki covers commands, permissions, and every configuration option.
Does Grim anticheat support Fabric servers?
Grim also ships a separate Fabric build alongside the Bukkit family builds. It targets Fabric server environments from 1.16.1 through the current 26.2 release and is maintained on the same release cadence, though most Grim installs run on Paper or Spigot.
Will Grim anticheat cause false bans on my server?
No anticheat is completely free of false positives, including Grim. Its checks are prediction based, comparing what a client reports against what should be physically possible, so laggy connections or unusual hardware can occasionally trigger a flag. Review punishments before enabling automatic bans and tune sensitivity for your player base.
