Byte-stable
Repeated runs are byte-identical when the input bytes, options, Kurviq version, and platform are unchanged. Cache and review generated assets with confidence.
Raster → SVG for Node.js
Pixels in. Curves out.
Kurviq traces PNGs and JPEGs into clean SVG. WebAssembly engine, zero runtime dependencies, byte-identical output for the same input and options — every run, every platform.
One command
npx kurviq --input in.png --output out.svg- Runtime deps
- 0
- Engine
- Wasm
- Node.js
- 18+
Why Kurviq
Built for pipelines, not dialogs.
Repeatable, scriptable, cacheable — the same bytes on every run.
Self-contained Wasm
The vector engine ships with the package. There is no separate native executable to install and no runtime dependency tree to pull into production.
CLI and Node API
Use the command line in asset scripts, or call the synchronous CommonJS API with a Buffer or Uint8Array. The same options apply in both surfaces.
Capabilities
Recipes for difficult pixels.
Start with defaults, then add one deliberate correction for the source you actually have.
--upscale 2 
Upscale before tracing
Use --upscale 2 for small labels and fine edges. Kurviq expands the working pixels while preserving the original SVG display size.
--remove-background auto 
Remove real backgrounds
Border-connected removal handles uniform cells and attached neutral shadows, with channel protection for narrow gaps and near-white artwork.
--alpha-mode auto 
Handle soft alpha
Auto mode detects meaningful partial transparency, resizes alpha-aware, and thresholds the result without letting hidden RGB bleed into the trace.
--sharpen 
Sharpen flat artwork
Recover a compact palette from blurry icons before vectorization. The bare flag uses at most 12 colors and stays deterministic.
--mode spline 
Fit smooth splines
A tested spline recipe keeps rounded icon contours smooth without over-segmenting every anti-aliased edge.
--gradient_step 8 
Preserve gradients
Smaller gradient steps and full color precision retain soft shading when visual fidelity matters more than the smallest possible SVG.
Real outputs
Drag across raster and SVG.
These are real Kurviq traces, including small icons and a full infographic. File sizes are the source files shown.
Illustrations traced by Kurviq itself.
See all seven examples →
SVG Raster Doctor — soft-shaded 3D icon
Fine facial details, soft shadows, and rounded color transitions.
SVG Raster Barcode — small outline icon
Narrow bars and soft-alpha edges on a compact source.
SVG Raster Choice path — full illustration
A 1,448 × 1,086 illustration with small labels and broad flat regions.
The traced SVG is 131 KB at DSSIM 0.003 (lower is closer).
Install and run
One package. Two entry points.
Install from npm, run the CLI immediately, or convert bytes and files from CommonJS.
CLI
Terminal
npm i kurviq
npx kurviq --input in.png --output out.svgNode API
JavaScript
const fs = require('node:fs');
const { convert, convertFile } = require('kurviq');
const svg = convert(fs.readFileSync('in.png'), {
mode: 'spline',
upscale: 2,
alphaMode: 'auto',
});
convertFile('in.png', 'out.svg', { preset: 'poster' });