Native macOS network diagnosis
Know where the lag starts.
LagCulprit watches the different legs of your connection and explains whether a slowdown most likely begins on your Mac, at your router, with your ISP, in DNS, or on the service you are using.
Current release · macOS 14+ · DMG
LagCulpritWhat it does
An answer, not another network dashboard.
LagCulprit continuously compares your gateway, independent public controls, DNS, Wi-Fi context, and the active application path. When conditions change, it turns those measurements into a plain-language verdict and keeps the supporting evidence locally.
A quiet menu-bar status and optional overlay show live health.
Mark the exact moment lag is felt with Option-Shift-M.
Review exact incidents, session recaps, and network reports.
The actual app
Quiet when healthy. Clear when it matters.
The menu-bar popover carries the full explanation. The floating overlay scales from a single latency number to a compact health summary or an expanded live view.
Any lag is likely the game server.
How it decides
Find the first point where healthy becomes broken.
Measurements alone say that something is slow. Agreement between controls shows where the failure probably begins.
Local network
The router or the connection between your Mac and the router stops responding.
ISP / upstream
The router stays reachable while independent internet controls fail together.
DNS
Internet reachability still works, but name lookups fail.
Application path
General controls stay healthy while a previously healthy service path degrades.
Attribution is probabilistic. If the evidence is mixed or incomplete, LagCulprit reports the source as inconclusive instead of inventing certainty.
Private by design
Your network history stays on your Mac.
The Rust daemon performs probing and diagnosis without root access or a privileged helper. History is stored locally in SQLite, retention is configurable, and reports are exported on your machine.
Monitoring creates lightweight probe traffic. The optional eight-second Session Preflight also performs a controlled temporary download capped at roughly 24 MB; it does not upload data or retain the payload.
macOS 14+ · direct download
Was it your internet, or was it the server?
Download the current DMG directly, or inspect and build the project from source on GitHub.