Frame Profiler
- By
Lightweight client-side frame-time profiler for Fabric 26.3 (FPS, 1% lows, render buckets, localhost AI API).
Frame Profiler
Lightweight client-side frame-time profiler for Fabric (Minecraft 26.3). It tells you why the game stutters, not just your average FPS.
Features
- Every second it logs FPS, average frame time, 1% low (99th-percentile frame time) and the worst frame.
- Rough CPU-side render-pipeline breakdown: terrain, entities, particles, block_entities, sky (sky/weather/fog), gui (GUI/hand/screen effects), other.
- Press P (rebindable under Controls > Miscellaneous) to write an instant SNAPSHOT line covering the last 1000 frames.
- Localhost-only JSON API at http://127.0.0.1:29514 for overlays, scripts and AI assistants. It never listens on the network.
- Low overhead: a 1000-frame ring buffer, System.nanoTime() timing and asynchronous log writes.
Install
- Install Fabric Loader 0.20.1+ for Minecraft 26.3 and Fabric API.
- Put frameprofiler-1.0.0.jar in your mods folder. You only need it on the client.
Reading logs/frame-profiler.log
- fps / avgMs: the average over that second.
- p99Ms: 99% of frames were at or under this time. low1Fps = 1000 / p99Ms is the "1% low FPS". If it is far below fps, you have stutter.
- maxMs: the single worst frame (a hitch).
- Buckets: average milliseconds per frame spent in that section, and its share of total frame time. other covers everything not attributed, including GPU waits, vsync/frame limiter, ticking, and chunk uploads.
Local API (127.0.0.1 only)
Port: -Dframeprofiler.port=29514. Disable it with -Dframeprofiler.http=false.
- /health returns {"ok":true}
- /stats returns current FPS, 1% low, max frame time and per-bucket ms/percent ({"ready":false} until the first full second)
- /stats/raw returns the most recent frame times in ms, oldest first
License: MIT. Author: Ashtonite365.
Frame Profiler Team
