Anti Player Crasher
Anti Player Crasher is a Fabric client-side mod that filters malicious packets sent by servers, so a client stays stable when a server sends crash-inducing data.
What it does
Blocking applies to three packet families: position packets with malicious values, explosion packets built to overload the client, and particle packets that carry invalid data. Each incoming packet is checked for non-finite and extreme numeric values, and the ones that fail the check are dropped before the game processes them. Gameplay itself is left as it is, and no new blocks, items or mechanics are added.
The mod was built after the PlayerCrasher-style server plugins that abuse these packet types, and it only hardens how the client handles them. It needs no installation on the server, so a server owner does not have to do anything. Connecting to an untrusted server is the case it is meant for, since the client is the side that receives the packets.
The file targets 1.21.10 only, on Fabric, and is released under the MIT License. The code is not open source, and the logo is plainly AI generated, which the author states openly.
Key features
Malicious position packets
Position packets with values that would move or misplace the player are blocked before the client applies them.
Malicious explosion packets
Explosion packets crafted to overload the client are filtered out, so the game does not process them.
Malicious particle packets
Particle packets carrying invalid data are dropped, which keeps the particle system from being driven into a crash.
Non-finite value detection
Numeric fields holding non-finite or extreme values are detected and the packet is rejected.
Unchanged gameplay
The mod only filters packets and leaves the gameplay, interface and features of the game as they are.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Anti client crasher covers Fabric builds for 26.1 – 26.1.2 and is client-side only under the CC0 1.0 Universal license, which is not open source. Packet Ninja is also client-side only, is open source under the GNU Lesser General Public License v3.0 only, and targets 1.21.8 – 1.21.11. NoClientExploits is client-side only under the MIT License, not open source, with files for 1.21.4 – 1.21.11. Anti Player Crasher's range is narrower, a single version, 1.21.10.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Anti Player Crasher | Fabric | 1.21.10 | Client-side only | 2026-02-20 |
| Anti client crasher | Fabric | 26.1 – 26.1.2 | Client-side only | 2026-05-22 |
| Packet Ninja | Fabric | 1.21.8 – 1.21.11 | Client-side only | 2026-03-28 |
| NoClientExploits | Fabric | 1.21.4 – 1.21.11 | Client-side only | 2026-07-14 |
Questions
Does Anti Player Crasher need Fabric API?
Does the server need this mod installed?
Which game version does the mod support?
Does the mod change how the game plays?
In the catalog
Anti Player Crasher is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 15,569 mods support Minecraft 1.21.10.
Similar mods
What the author says
AntiPlayerCrasher is a lightweight client-side Fabric mod for Minecraft 1.21.10 that protects your game from malicious packet-based crash attempts. Some exploit plugins and abusive servers send intentionally broken packet data to force client crashes. This mod intercepts the most common crash packet paths and…
Official listing
- Modrinth page
- modrinth.com/mod/anti-player-crasher
- Owner
- Redstone Development
- Published
- 2026-02-20
- Updated on Modrinth
- 2026-02-20
- Facts verified
- 2026-10-15