GridPoint — Location Format Explorer

A web application for converting between location formats and visualising points on an interactive map.

Screenshot

Supported Formats

Format	Input	Output
Latitude/Longitude — Decimal Degrees	✅	✅
Latitude/Longitude — Degrees Minutes Seconds	✅	✅
Latitude/Longitude — Degrees Decimal Minutes	✅	✅
Maidenhead Grid Locator	✅	✅
UK Postcode	✅	—
Town / Place Name	✅	—
OS Grid Reference	✅	✅
WAB Square	✅	✅
Plus Code	✅	✅

Quick Start

With Docker Compose (recommended)

docker-compose up --build

Then open http://localhost:8080

With Docker directly

docker build -t gridpoint .
docker run -p 8080:8080 gridpoint

To change the port

docker run -p 9000:8080 gridpoint
# then open http://localhost:9000

Usage

To locate a point:

1. Select an input format from the dropdown
2. Enter the location value(s)
3. Press LOCATE or hit Enter

To decode a map point:

• Click anywhere on the map — all formats for that location appear in the sidebar

To get bearing and distance between two points:

1. Open the BEARING tab — point A starts at your located point, if there is one
2. Set A and B by typing a location in any input format and pressing SET, or by clicking the map (the highlighted point is the one the next click sets; use PICK ON MAP to choose)
3. The sidebar shows the true bearing both ways, plus the great-circle distance in km, miles and nautical miles; the map draws the great-circle path

To change the map style:

• Use the Street / Satellite / Topo switch in the top-right corner of the map

To copy a format:

• Click the ⧉ icon next to any result

Notes

• OS Grid Reference, WAB Square conversions apply to Great Britain only
• UK Postcode lookup uses the free postcodes.io API
• Town/place lookup uses OpenStreetMap Nominatim
• Map tiles come from OpenStreetMap, Esri and OpenTopoMap; none require an API key

Running Without Docker

cd app
python server.py

Requires Python 3.8+ — no additional packages needed.

Author

Built by James Marshall (M0LZN) — m0lzn.com