Source-checkedAdmin & protection

BetterGrim

by DieInCalamity · for Minecraft

A fork of Grim AntiCheat, adding new checks, optimizing and making better existing checks

10KDownloads
6 mo agoLast updated
GPL-3.0-or-laterLicense
Bukkit · Fabric +4Loaders

About BetterGrim

From Modrinth

A fork of Grim AntiCheat, adding new checks, optimizing and making better existing checks

I archived it because I'm tired of working on this project and there are much better alternatives. But maybe sometime I will remake this project

BetterGrim is an open source GrimAC fork designed to have fixes of false positivies and bypasses of upstream. It currently supports minecraft versions from 1.8 to 1.21.11. Geyser players are fully exempt from the anticheat to prevent false positives. This project is considered feature-complete for the 2.0 (open-source) branch. If you would like a bug fix or enhancement and cannot sponsor the work, pull requests are welcome. It is recommended to use latest alpha(dev) build to have latest fixes, changes and checks (note: Changelogs on Modrinth may not show the full changelog, for full changelog go to GitHub Commits)

What changes do BetterGrim currently have that upstream does not

  • NoWeb check - fixes NoWeb bypasses
  • AutoClicker checks (reworking)
  • Invalid checks
  • Inventory checks
  • Fix tick-based NoSlow bypasses
  • Change NoSlow mitigation to resetItemUsage instead of setbacks (safer)

Downloads

  • Latest updates:
  • GitHub

artifacts: Bukkit, Fabric (bleeding edge)

Requirements & Installation

If you use a proxy such as Velocity or Bungeecord:

  • If you use Geyser, Floodgate must be installed on the backend server (where Grim is) so Grim can access the Floodgate API.
  • If you use ViaVersion, it must be installed on the backend server (where Grim is) ONLY.

Grim does not support having ViaVersion installed on the proxy, even if it is also installed on the backend.

Resources

  • For documentation and examples visit the Wiki.
  • For answers to commonly asked questions visit the FAQ.
  • For community support and project discussion join our Discord.

Pull Requests

See Contributing for more information about contributing and what our guidelines are.

Developer Plugin API

Grim's plugin API allows you to integrate Grim into your own plugins. Visit the plugin API repository for the source code and more information.

Compiling From Source

  1. git clone https://github.com/DieInCalamity/BetterGrim
  2. cd Grim
  3. ./gradlew build
  4. The final jars will compile into the <platform>/build/libs folders

Grim Supremacy

What makes Grim stand out against other anticheats?

Movement Simulation Engine

  • We have a 1:1 replication of the player's possible movements
  • This covers everything from basic walking, swimming, knockback, cobwebs, to bubble columns
  • It even covers riding entities from boats to pigs and striders
  • Built upon covering edge cases to confirm accuracy
  • 1.13+ clients on 1.13+ servers, 1.12- clients on 1.13+ servers, 1.13+ clients on 1.12- servers,

and 1.12- clients on 1.12- servers are all supported regardless of the large technical changes between these versions.

  • The order of collisions depends on the client version and is correct
  • Accounts for minor bounding box differences between versions, for example:
  • Single glass panes will be a + shape for 1.7-1.8 players and * for 1.9+ players
  • 1.13+ clients on 1.8 servers see the + glass pane hitbox due to ViaVersion
  • Many other blocks have this extreme attention to detail.
  • Waterlogged blocks do not exist for 1.12 or below players
  • Blocks that do not exist in the client's version use ViaVersion's replacement block
  • Block data that cannot be translated to previous versions is replaced correctly
  • All vanilla collision boxes have been implemented

Fully asynchronous and multithreaded design

  • All movement checks and the overwhelming majority of listeners run on the netty thread
  • The anticheat can scale to many hundreds of players, if not more
  • Thread safety is carefully thought out
  • The next core allows for this design

Full world replication

Read the full description on Modrinth →

Highlights

From source data

Game versions

Supports 82 Minecraft versions, the newest being 26.1.2.

Loaders

Runs on Bukkit, Fabric, Folia, Paper, Purpur and Spigot.

Footprint

Rated a light load on a server.

BetterGrim on Nxeon

From our catalogue
One-click install
Supported on Nxeon Minecraft servers. We download it from Modrinth, place it, and restart the server.
Server type needed
Bukkit, Fabric, Folia, Paper, Purpur, Spigot
Server load
light
Smallest plan we suggest
Minecraft — 2 GB (2 GB RAM). This follows our own load rating above, not a benchmark.
Latest build
2.3.74-a3a95cc (alpha), released 2026-04-24

Game versions by loader

LoaderGame versionsNewest
Bukkit1.7.2 to 26.1.2 (82 versions)26.1.2
Folia1.7.2 to 26.1.2 (82 versions)26.1.2
Paper1.7.2 to 26.1.2 (82 versions)26.1.2
Purpur1.7.2 to 26.1.2 (82 versions)26.1.2
Spigot1.7.2 to 26.1.2 (82 versions)26.1.2
Fabric1.16.1 to 26.1.2 (37 versions)26.1.2

From 5 recorded builds of BetterGrim.

Recent builds

BuildReleasedGame versionsLoaders
2.3.74-a3a95cc alpha2026-04-241.7.2 to 26.1.2 (82 versions)Bukkit, Folia, Paper, Purpur, Spigot
2.3.74-a3a95cc alpha2026-04-241.16.1 to 26.1.2 (37 versions)Fabric
2.3.74-aad5c59 alpha2026-04-231.7.2 to 26.1.2 (82 versions)Bukkit, Folia, Paper, Purpur, Spigot
2.3.74-aad5c59 alpha2026-04-231.16.1 to 26.1.2 (37 versions)Fabric
2.3.74-675fba3 alpha2026-04-181.7.2 to 26.1.2 (82 versions)Bukkit, Folia, Paper, Purpur, Spigot

Dependencies

  • Required: modrinth project P7dR8mSH (modrinth, not in our catalogue)

Declared by the newest build that lists any. Required ones are installed with it on one-click installs.

Run BetterGrim on a Minecraft server

Pick a server or deploy a new one above; it is installed in one click.

What kind of mod it is

From the catalog
Listed on Modrinth as “Mods”

Admin & protection

Permissions, moderation, anti-cheat and land protection for the people running the server.

Compatibility

Game
Minecraft
Loaders
BukkitFabricFoliaPaperPurpurSpigot
Game versions
26.1.2 and 81 earlier

Verified at the source

  • ✓ModrinthOfficial listing, checked 2026-10-02Open ↗
  • ✓AuthorDieInCalamity, as published on Modrinth
  • ✓LicenseGPL-3.0-or-laterFree

BetterGrim, answered

Generated from the mod’s own source data.

Which loaders does it support?

Bukkit, Fabric, Folia, Paper, Purpur and Spigot.

Is it free?

Yes. BetterGrim is free to download from Modrinth. Its license is GPL-3.0-or-later.

How do I add it to my Nxeon server?

Use “Add to a server” on this page, or open NxLabs from your dashboard. We install it, restart your server and switch it on.

NxLabs

Run BetterGrim on a Minecraft server.

Deploy in about a minute from $4.99 a month, then add BetterGrim in one click.