HardProof
by Unlstd
HardProof is a Fabric client mod that checks whether a selected Minecraft world has been altered with cheats or inappropriate activity.
What it does
The mod inspects a chosen singleplayer world and reports whether it shows signs of cheating, such as open LAN with cheats enabled, operator privileges granted to players, or a game mode other than survival set to 0. It is aimed at people who want to show friends that a world was played without outside help, and at anyone who has not yet decided whether to trust a world someone else made.
Restoring a world after a death through backups is noted as useful when playing hardcore in beta builds. The author states that cheat client detection is not yet implemented, and that the checks work in most cases rather than all of them. HardProof is client-side only, so only the player running the check needs it, and it is released under the MIT License as open source, with its source code published.
Key features
Cheat-setting checks
The mod looks at whether open LAN cheats are enabled in the selected world.
Operator privilege checks
Operator privileges granted to players in the world are detected and listed.
Game mode check
The check flags a world whose game mode is not survival, which is set to 0.
Backup restoration
Restoring a world after dying from a backup is supported, which helps when playing hardcore in beta.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Verifying a shared world
A player can check a world before inviting friends to confirm that it was played with the default rules.
Trusting an unfamiliar save
Someone who receives a world made by another player can run the checks before relying on its progress.
Who it’s for: Players who want to confirm a singleplayer world was played without cheats, and players who share survival worlds and want a way to show that. The checks are heuristics, so a clean result does not prove the world is pure.
How it compares
HardProof is a Fabric, client-side only mod released under the MIT License as open source, with files for 1.21.5 – 1.21.8. Poime's Mod Checker is also open source under the MIT License and runs on client and server, but its files cover only 1.21.4. Defixus Anti-Cheat is closed source under All rights reserved, runs on client and server, and covers 1.21.4 – 26.3, so it targets a different job.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| HardProof | Fabric | 1.21.5 – 1.21.8 | Client-side only | 2025-09-18 |
| Poime's Mod Checker | Fabric | 1.21.4 | Client and server | 2025-05-26 |
| Defixus Anti-Cheat | Fabric | 1.21.4 – 26.3 | Client and server | 2026-10-03 |
Questions
Does HardProof need to be installed on a server?
Which game versions does HardProof support?
Can HardProof detect every kind of cheat?
In the catalog
HardProof is one of 29,952 Game mechanics mods on ModsFinder, and one of 19,630 Game mechanics mods for Fabric. 17,695 mods support Minecraft 1.21.8.
More from Unlstd
Similar mods
What the author says
This mod let's you check for inappropriate activity on your selected minecraft world, its mainly purpose is to show your friends that you've never cheated on some worlds if they dont trust you enough. *Performium is a great modpack that optimizes your game made by KasaiSora
Official listing
- Modrinth page
- modrinth.com/mod/hardproof
- Owner
- Unlstd
- Published
- 2025-09-08
- Updated on Modrinth
- 2025-09-18
- Facts verified
- 2026-10-15