How to Stop Getting Kicked for Moving Too Fast on a Server

What the mod actually changes

Vanilla servers run a movement check that compares where the server thinks you are against where your client says you are. If the gap is too large, the server rubber-bands you back or disconnects you with a "moved too quickly" or "moved wrongly" message. I'm Fast Mod patches those checks out with mixins, so the server stops treating fast movement as cheating.

Getting it working

1. Install the mod on the server, not the client. It is server-side, so players joining with a vanilla client still benefit.

2. Restart the server so the mixins load.

3. Join and test with a normal sprint first, then escalate to whatever speed source you use (a modded speed effect, a fast vehicle, an elytra boost, a teleport-heavy setup).

4. If you still get kicked, the disconnect is coming from something other than the vanilla movement check — check for an anticheat plugin or a separate movement-limiting mod, since those run their own logic and won't be disabled by this mod.

Things to know

Removing the check means the server no longer validates your position aggressively. On a public server this can look like cheating to other players, so use it on servers you control or where the owner has agreed. On singleplayer/LAN the check barely matters, but the mod still helps if you run an integrated server with high-speed mods.