Maps & geo tools
Coordinates, great circles, sunlight and map rendering — computed entirely in your browser, so your locations never leave your device.
Most popular
Coordinate Converter
Convert between decimal degrees, DMS, UTM, MGRS, geohash and Plus Codes — with a map.
popular
Great Circle vs Rhumb Line
Why flights look curved on the map: shortest path vs constant bearing between any two points.
popular
Planetarium & Star Chart
The whole sky over any place and time: stars, constellations, planets, the Moon and satellite passes.
popular
Star Photo Identifier
Drop a photo of the night sky and every star, constellation and nebula in it is found and named, along with where the camera was pointing.
Coordinates & Distances
Coordinate Converter
Convert between decimal degrees, DMS, UTM, MGRS, geohash and Plus Codes — with a map.
popular
Great Circle vs Rhumb Line
Why flights look curved on the map: shortest path vs constant bearing between any two points.
Antipode Finder
Click any point on Earth and see where you would come out if you dug straight through.
Sun & Time
Planetarium & Star Chart
The whole sky over any place and time: stars, constellations, planets, the Moon and satellite passes.
popular
Star Photo Identifier
Drop a photo of the night sky and every star, constellation and nebula in it is found and named, along with where the camera was pointing.
Day & Night World Map
Live sunlight terminator on a world map, with date and time sliders.
Solar Time vs Clock Time
How wrong is your clock? See the gap between official time and sun time anywhere on Earth.
Map Viewers & Rendering
About these tools
Geography and map utilities for the curious and the practical: convert coordinates between every common format, compare flight paths, find antipodes, watch the day-night terminator move, and render maps in vintage engraving style. Everything is computed locally in your browser.