AltDetector icon

AltDetector -----

AltDetecor, AltCheck



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Altdetector1.png AltDetector2.png

AltDetector

A simple, fast alt-account detector for 1.19-1.21.X — alerts staff when players share IPs.
Author: Silverninja3_
✅ What is it?
AltDetector checks players on join and notifies staff when the connecting player shares an IP with other accounts. Messages support & color codes, hex colors, and MiniMessage gradients so you can style alerts exactly how you want.

✨ Features

  • Detects alts by shared IP on join
  • Sends alerts to altdetector.notify and OPs (configurable, OPs see by default)
  • Beautiful, customizable messages with & codes, hex (&#RRGGBB or <#rrggbb>), and <gradient:...>
  • /alt command:
    • /alt shows a clickable list of online players
    • /alt <player> checks that player’s alts
    • Tab-completion for online names
  • /altdetector lookup <player> — check any player in the datastore
  • /altdetector reload — hot-reload config + data
  • Name preview limit (e.g. "User1, User2 (+3 more)")
  • Privacy option: store real IPs or SHA-256 hashed keys
  • Exempt trusted users from checks/storage
  • Console also receives alerts

Requirements

  • Java 21
  • Minecraft server 1.21.4 (built against Paper API; works on modern Paper/Spigot with Adventure)
Installation
  1. Drop the jar in plugins/
  2. Start the server once to generate config/data
  3. (Optional) Edit plugins/AltDetector/config.yml to customize messages and behavior
  4. Grant staff the permissions below
️ Commands
Code (Text):

/alt                      - Clickable list of online players to check
/alt <player>             - Check a specific player's alts
/altdetector reload       - Reload config + data store
/altdetector lookup <p>   - Show other names seen on the same IP as <p>
 

Permissions

Permission Description Default
altdetector.notify See alt alerts on player join op
altdetector.check Use /alt to check players op
altdetector.admin Use /altdetector reload & lookup op
altdetector.exempt Player is exempt from detection & storage false

Note: OPs always see alerts by default (configurable via ops-always-see).

⚙️ Configuration

Code (YAML):

notify-permission
: "altdetector.notify"
ops-always-see
: true
min-matches
: 1
name-preview-limit
: 5
# Placeholders: {player}, {ip}, {matches}, {count}
alert-format
: "<gradient:#ff6a00:#ffd800>[AltDetector]</gradient> &e{player} &7shares IP with &c{matches} &7(&f{ip}&7)"
no-matches-format
: "<gradient:#6a86ff:#b86bff>[AltDetector]</gradient> &aNo matches for &e{player}&a."
# Store real IPs (true) or SHA-256 hashed keys (false)
store-plain-ip
: true
 
Placeholders
  • {player} – the player being checked
  • {ip} – the stored IP or hashed key
  • {matches} – comma-separated preview of matched names
  • {count} – total number of matching names (excluding {player})
Formatting
  • & codes: e.g. &6&lGold Bold
  • Hex: &#FFAA00 or <#ffaa00>
  • Gradients: <gradient:#ff6a00:#ffd800>Your Text</gradient>
Examples
Code (Text):

/alt
# -> clickable list of online players; click a name to run /alt <name>
/alt Silver
# -> shows "Silverninja3_ shares IP with Name1, Name2 (+2 more) (1.2.3.4)"
 

Privacy

  • Set store-plain-ip: false to store only a SHA-256 hash key and show that in alerts
  • Grant altdetector.exempt to trusted players/accounts to skip storage and alerts

Changelog

  • 1.0.0 — Initial release: join alerts, /alt with clickable list & tab-complete, /altdetector reload & lookup, styled messages (&, hex, gradients), IP hashing option, exemptions.
Resource Information
Author:
----------
Total Downloads: 5
First Release: Sep 2, 2025
Last Update: Sep 2, 2025
Category: ---------------
All-Time Rating:
1 ratings
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