Lag Visualizer

Lag Visualizer

See what actually caused your lag spike!

(Note: Any features seen here but not in game will be added at some point. I made this description before the mod lol.)

Lag Visualizer is a lightweight client-side performance diagnostic mod for Minecraft that helps you understand why your game stutters, freezes, or suddenly drops frames.

Instead of only showing FPS, Lag Visualizer monitors frame times and other performance metrics in real time, detects major stutters, and analyzes what was happening when they occurred.

Features

Detects significant frame-time spikes

Tracks FPS, frame time, memory usage, entities, chunks, and more

Identifies likely causes of stutters

Uses confidence-based diagnostics rather than pretending every result is certain

Shows optional lag-spike notifications

Includes a compact performance overlay

Records recent stutters for later inspection

Displays frame-time history and graphs

Exports diagnostic reports for troubleshooting

Designed to have very low performance overhead

What Can It Detect?

Lag Visualizer can attempt to identify stutters related to:

Chunk loading

Chunk rebuilding

Garbage collection

High memory usage

Large entity counts

Block entities

Particle load

Resource reloads

Rendering load

Unknown or unclassified spikes

For example:

143 ms stutter

Likely cause: Chunk Loading

Confidence: 87%

Diagnostics are based on the performance data collected around each spike, so causes are shown as estimates rather than guaranteed answers.

Performance Dashboard

Open the Lag Visualizer dashboard to view information such as:

Current FPS

Current frame time

Average FPS

1% low FPS

Memory usage

Loaded chunks

Entity count

Block entity count

Session stutter count

Recent frame-time history

Detected spikes are marked on the graph so you can see exactly when performance problems happened.

Stutter History

Lag Visualizer keeps a history of recent performance spikes.

Each event can include:

Exact frame duration

Time of the spike

Suspected cause

Confidence level

Relevant performance metrics

Diagnostic explanation

This makes it much easier to investigate recurring stutters instead of guessing what caused them.

Diagnostic Reports

Lag Visualizer can export troubleshooting reports containing useful performance information such as:

Minecraft version

Fabric Loader version

Lag Visualizer version

Java version

Memory allocation

Installed mods

FPS statistics

Recorded stutter events

Diagnostic results

Reports are designed for troubleshooting and avoid including unnecessary private information such as usernames, server addresses, access tokens, or personal filesystem paths.

Compatibility

Lag Visualizer is designed to work alongside performance mods rather than replace them.

It aims to remain compatible with mods such as:

Sodium

Lithium

FerriteCore

ModernFix

ImmediatelyFast

Iris

Entity Culling

More Culling

Compatibility may vary depending on Minecraft and mod versions.

Client-Side

Lag Visualizer is a client-side mod.

Servers do not need to install it.

Why Lag Visualizer?

Most performance tools tell you:

“Your FPS dropped.”

Lag Visualizer is built to help answer the more useful question:

“Why did my game just freeze?”

If Minecraft normally runs smoothly but randomly stutters, freezes while loading chunks, or experiences unexplained frame-time spikes, Lag Visualizer is built to help you figure out what happened.