Login System
by notch99
Login System is a server-side mod for offline-mode servers that requires players to register and log in before they can take part in the game.
What it does
Players who join an offline-mode server must authenticate before they can interact with it. Until a player logs in, movement and interaction are restricted, and the mod can kick players who never authenticate. Once a player registers or logs in, the server restores the position the player had when joining.
Before login the player's inventory is hidden and a blindness effect is applied, so an unauthenticated session shows nothing useful. A configurable waiting area can be set as the place a player is teleported to while waiting. Duplicate connections using the same UUID are blocked, and the second session is disconnected. Each option is documented with comments in the configuration file. The mod is open source under the MIT License and runs on server only, so players join without installing it. Files are published for Fabric, Forge and NeoForge, across 21 release versions, 1.20 – 26.2.
Key features
Registration and login
Players register a password on first join and log in on later joins, before any interaction with the server is allowed.
Movement and interaction lock
A player who has not logged in is kept from moving or interacting, which blocks impersonation of existing accounts.
Waiting area and position restore
A configurable waiting area holds unauthenticated players, and the original position is saved and restored after a successful login.
Inventory hiding
The inventory of an unauthenticated player is hidden and a blindness effect is applied until login is complete.
Double login prevention
A second connection with the same UUID is blocked, and the duplicate session is disconnected.
Compatibility
Latest build for each game version and loader.
26.x4 of 4 versions with builds
1.21.x12 of 12 versions with builds
1.20.x5 of 5 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Offline-mode servers
Servers that accept players without Mojang authentication can use the mod to require a local login before play.
Who it’s for: Server owners who run offline-mode servers and want players to authenticate before they can move, interact or see their inventory.
How it compares
Login Security - Panda is a NeoForge-only server mod for 1.21.1 – 1.21.4 under All rights reserved, and it is not open source. safeserver is a Fabric server mod for 1.20.1 – 26.3 under the MIT License, so it is open source. Stupid Login is for Forge and NeoForge across 1.20.1 – 1.21.1 and runs on client and server, so it needs installing on the client as well.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Login System | Fabric, Forge and NeoForge | 1.20 – 26.2 | Server-side only | 2026-08-24 |
| Login Security - Panda | NeoForge | 1.21.1 – 1.21.4 | Server-side only | 2025-09-20 |
| safeserver | Fabric | 1.20.1 – 26.3 | Server-side only | 2026-09-20 |
| Stupid Login | Forge and NeoForge | 1.20.1 – 1.21.1 | Client and server | 2026-08-03 |
Questions
Which loader should a server use for Login System?
Do players need to install Login System?
Which game versions are covered?
In the catalog
Login System is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 13,894 mods support Minecraft 26.2.
More from notch99
Similar mods
What the author says
Login System is a simple yet powerful mod that adds a registration and login system for offline-mode Minecraft servers. It ensures players must authenticate before playing, preventing impersonation and unauthorized access. Player Authentication Players must /register and /login before interacting with the server.
Official listing
- Modrinth page
- modrinth.com/mod/loginmod
- Owner
- notch99
- Published
- 2025-08-21
- Updated on Modrinth
- 2026-08-24
- Facts verified
- 2026-10-15