GeomKit

Paste WKT, EWKT, hex WKB or GeoJSON, see every geometry on a map, edit it, and copy it back as WKT, EWKT, WKB, SQL or GeoJSON. Runs in your browser; nothing is uploaded.

Reads WKT, EWKT, hex WKB and GeoJSON. Writes WKT, EWKT, hex WKB, SQL and GeoJSON.