Chart an island that doesn't exist -- coastline, contours, port, peak, and compass rose, reproducible from the seed on its card.
Contour lines connect points of equal elevation, so each ring on a map traces where the land crosses one particular height. Where the rings crowd together the slope is steep -- climbing there means gaining height quickly -- and where they spread apart the ground is nearly flat. Reading them takes one convention: closed rings nested inside each other mean a summit (or, with tick marks, a depression), and the innermost ring is the highest ground. Invented in the eighteenth century for charting rivers and coastlines, the technique still underlies every topographic map, and it's what gives this generator's islands their instantly map-like look.
Every press charts an island that doesn't exist: a coastline of bays and headlands built from seeded harmonics, nested elevation contours rising to a marked peak, a port town on the shore, wave marks in open water, and a compass rose -- named like a chart from a lost atlas, Vashmere to Korholm Isle. The seed on the card resurveys any island exactly.
Every result here is drawn using crypto.getRandomValues() -- the Web Crypto API's cryptographically secure randomness -- instead of Math.random(), so it's genuinely unpredictable, not just statistically random. Learn more.
Worldbuilders and game masters get a campaign setting in one press -- the island, its capital port, and its mountain are a story seed by themselves. Writers use the names alone; teachers use the contour rings to explain topographic maps with land no one can argue about. The SVG copy button takes the chart into any editor at any size.
Each press draws a 32-bit seed from the site's cryptographically secure randomness and surveys the island from it: the coastline radius is a sum of four sine harmonics -- low frequencies shape the landmass, a higher one carves bays -- and the contour rings are scaled copies of the same curve, which is why they nest plausibly. The port is dropped on the coast itself, the peak near the interior's centre, and every name is assembled from the same seed, so chart and gazetteer always agree.
They're elevation contours, exactly as on a real topographic map: each ring is higher ground than the one outside it, climbing to the purple peak marker at the top of the island.
Yes -- coastline, contours, port, peak, and every name are determined by the seed stamped on the card.
Freely -- the SVG button in the card's corner copies the chart as a vector file that rescales cleanly for handouts, virtual tabletops, or book interiors.
Quest Hook · Magic Item · Monster · NPC · Tavern Name · Spell Name