Seeded Identity Mark

About this asset

Generative avatars are a solved problem that almost every implementation still gets wrong in the same three ways. The first is reaching for Math.random, which on a server-rendered page is a hydration mismatch and, more importantly, means a user's mark changes every time they reload — the one thing an identity mark must never do. Everything here comes from an FNV-1a hash of the seed feeding an xorshift stream, so the same string yields the same mark on any machine, forever. The second is filling the grid with independent coin flips, which produces something that reads as a QR code rather than a glyph; generating one half and reflecting it, over an odd-sized grid so there is a real centre column to hang the design on, is what makes the eye accept it as a mark. The density is also graded from sparse at the edges to dense at the spine rather than flat, because a uniform fill is mush. The third is colour: letting the seed choose a full HSL triple regularly lands on a yellow that disappears against its own plate. Only the hue is seeded here; saturation and lightness are fixed, which guarantees every possible input produces something readable. Finally, draws that come out nearly empty or nearly solid are rejected and re-rolled from a salted seed — still deterministic, just a different draw.