CGEODATA demo

Search places

Layers

OpenStreetMap base map

Grid overlay

Each pixel is one query against the CGEODATA file, colored by a hash of the resolved place. Zoomed out past level 7, one query covers a block of pixels to keep tiles fast, so borders get blockier there. From level 8 in, lines mark where places meet: darker between regions, darkest between countries.

Overlay opacity 65%

Chunk grid

A lookup decompresses the one chunk its point is in. Zoomed in far enough, each chunk shows its compressed size and index.

Spot checks

Places from the country notes, looked up when this dataset was built.

Capitals

The dataset is older than its input, so failures may already be fixed in a newer build.

Dataset

The size of the finest cell, east–west × north–south, at the equator. Places smaller than that may have no cells of their own.

Downloads

Keep the file names: openFile() picks up the indexes next to the .bin. They're optional, and cgeodata build-search-index / build-locate-index build them from the .bin too.

Reader API docs