Local check · three screens · no upload
Test the screens your sketch will meet.
Catch fuzzy canvases, slow frames, laggy input, and brittle WebGL before your students or audience do.
cargo install sketch-density-check
Free, open source, and local-first. Requires a Chromium-family browser.
2× / 3×Backing-store fit
< 20 msFrame p95 budget
< 100 msInput-to-paint budget
0 uploadsYour work stays local
One command before publish
Three passes through the stall
The checker makes browser profiling legible without pretending a laptop can perfectly reproduce every phone.
- 01
Load the real sketch
Point at a folder or local dev URL. Assets and code stay on your machine.
- 02
Exercise each density
Capture phone and tablet frames, 120-frame traces, focus signals, reduced motion, and a WebGL-disabled fallback.
- 03
Read the publish card
Get direct pass, check, or fail language plus PNGs and JSON for CI.
Recorded demo
A result an artist can act on
Select a device profile to inspect the sample run. Arrow keys work on the selector.
Canvas backing store matches 390 × 844 CSS pixels at 2×.
Open the shutters
Check a sketch in one local run.
sketch-density-check ./my-sketch --out .sketch-check