Lag Detective

LagDetective

**Lag Detective is a lightweight Fabric diagnostics mod for Minecraft that helps you quickly understand why your game or server is lagging — without installing heavy profilers or complex tools.

It provides real-time performance monitoring, clear lag classification, and easy-to-read reports through simple commands and an optional client dashboard.**

What Lag Detective Does:

Lag Detective helps answer questions like:

- Is the lag coming from the server TPS or the client FPS? - Are you CPU/tick bound, GPU/render bound, or memory/GC stuttering? - Are too many entities loaded in one chunk? - Is chunk loading or world generation causing spikes? - What are the most likely causes right now?

Key Features:

Server Performance Tools:

- TPS and MSPT monitoring - Entity and chunk activity tracking - Server-side lag diagnosis - Support report generation

Client Diagnostics Dashboard

- FPS + frame time monitoring - Client tick time measurement - Memory + GC spike detection - Server metrics shown when available

Commands:

/ld status — server performance summary

/ld fps — current client FPS

/ld mspt — server tick time

/ld tps — server TPS estimate

/ld clientinfo — full client debug info

/ld serverinfo — full server debug info

/ld entity — chunk-by-chunk entity scan

/ld report — generate support report

/ld ui — open the diagnostics dashboard

Support Reports

Lag Detective can generate a complete diagnostic report for debugging or support requests:

- System + mod info - Current TPS/FPS/MSPT - Top lag causes with confidence scores - Recommended actions - Saved automatically as: `lagdetective-report.txt`

Designed for Safety & Compatibility

- Works on client + dedicated server - No mixins required - Lightweight sampling (default once per second) - Never modifies other mods or game settings - Suggestions are informational only

Perfect For:

- Server owners tracking TPS drops - Modpack developers diagnosing performance - Players experiencing stutters or frame lag - Debugging mob farms, chunk loaders, or heavy mods

Lag Detective: Find the cause. Fix the lag. Play smoothly.