Show HN: Browser-only 64-color Wplace image quantizer (no server, free)

[howardV]

Hi HN,

I play a lot of *[Wplace](https://wplace.live)*, the pixel-art world map that limits every drawing to the official 64-colour palette (32 free, 32 paid). Re-colouring images by hand was painful, so I built a *client-side tool* that:

* takes any PNG/JPG * maps each pixel to the nearest of the 64 official colours * lets you *toggle paid colours off* → no wasted droplets * adds optional Floyd–Steinberg dithering * shows live pixel / colour stats for cost estimation * exports a ready-to-place PNG or copies it to the clipboard (all computation in the browser, nothing uploaded)

*Link* <https://wplacecolorconverter.online>

*Tech notes*

* TypeScript + Vite + React + Tailwind * Pixel work happens in a Web Worker on an `OffscreenCanvas` * Quantisation is ~300 LOC (RGB Euclidean distance; optional error diffusion) * No back-end, so it runs offline and keeps images local

I’d love feedback on:

* performance for big images (>512 px) * better distance metrics (ΔE?) or a faster lookup table * whether a WebGPU / wasm port is worth it * other pixel-art communities that might need custom palettes

Thanks for reading!