SpyFilter
by ratger
SpyFilter hides chat lines that carry the SPY marker, so players who dislike spy-style messages can keep them out of their chat window.
What it does
Chat messages that contain the SPY BOOK or SPY SIGN markers can be switched on or off in the mod's settings. When hiding is turned on, those lines are removed from the chat window on the player's own client, while everything else in chat is left as it was. The filter works on plain-text terms, so a message is caught whenever its text includes one of the listed markers.
Because the messages can be split across several lines, the mod detects them with a regular expression rather than a simple word match. That lets it recognize a marked message even when the marker and the rest of the text arrive on separate lines. The mod changes nothing on any server, so it is only a matter of what one player chooses to see.
SpyFilter is a client mod for Fabric, published for the 1.21 range. It runs on a single-player world or a multiplayer connection alike, and the server does not need it. The code is not open source, and the mod is released under All rights reserved, so redistribution and modification are not granted by the author.
Key features
Toggle spy messages
Spy-marked chat messages can be shown or hidden with a switch in the mod's settings, without restarting the game.
Marker-based filtering
Lines containing the SPY BOOK or SPY SIGN markers are matched as plain terms and removed from the chat window.
Multi-line detection
A regular expression catches marked messages that span several lines, which a single-line match would miss.
Client-only action
Filtering happens only in the player's own chat window, so the server and other players see the same messages as before.
Gallery
Compatibility
Latest build for each game version and loader.
1.21.x12 of 12 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Quieter multiplayer chat
A player on a busy server can hide spy-marked lines so they do not clutter the chat window during play.
Who it’s for: Players on Fabric who want spy-marked chat messages removed from their own view, on a server or in single-player.
How it compares
Chat Sync is a Fabric mod for 1.21.10 – 1.21.11 under the MIT License, but it is not open source. Chat Filters is open source under the GNU General Public License v3.0 only and covers 1.21.9 – 26.2, so it reaches more versions. Both are client-side only, as SpyFilter is, but they filter chat in different ways and are not limited to the spy markers.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| SpyFilter | Fabric | 1.21 – 1.21.11 | Client-side only | 2026-03-10 |
| Chat Sync | Fabric | 1.21.10 – 1.21.11 | Client-side only | 2026-02-19 |
| Chat Filters | Fabric | 1.21.9 – 26.2 | Client-side only | 2026-07-27 |
Questions
Does SpyFilter need to be installed on the server?
Which Minecraft versions does SpyFilter support?
Can SpyFilter be modified or redistributed?
In the catalog
SpyFilter is one of 5,392 Social mods on ModsFinder, and one of 4,084 Social mods for Fabric. 19,862 mods support Minecraft 1.21.11.
Similar mods
Official listing
- Modrinth page
- modrinth.com/mod/spyfilter
- Owner
- ratger
- Published
- 2025-06-26
- Updated on Modrinth
- 2026-03-10
- Facts verified
- 2026-10-15