One glorious Randomize button. Every press invents a plausible new flag from real vexillological grammar — historically weighted layouts, tincture-aware colors, classic charges — plus a fictional country to fly it, and an instant NAVA critique. Everything runs in your browser.
The seed link reproduces this exact flag (seed + constraints in the URL). "Open in Flag Designer" hands the design over for editing; the Look-Alike Finder can't receive a design by link, so it opens fresh.
Same five principles the Flag Designer judges by: simplicity, meaningful symbolism, 2–3 colors, no lettering or seals, distinctiveness. Symbolism is yours to invent; the rest is computed.
Layouts are weighted by real-world frequency (tricolors common, quartered fields rare). Colors come from the traditional vexillological palette with a rule-of-tincture-ish check — adjacent panels avoid color-on-color and metal-on-metal where possible. Charges (stars, crescents, suns, birds, laurel…) appear at the center, canton or hoist depending on the layout, and sometimes not at all — just like real flags. Aspect ratios draw from real standards: 2:3 mostly, then 3:5, 1:2, 5:8, and the rare square.