Every trade has its fossils. Carpenters have imperial measurements, accountants have the fax machine, and GIS people have the Shapefile — a format from 1998 that consists of at least three files pretending to be one, limits field names to ten characters, and still ships as the default export from half the world's authorities.
We built gisformat.com because we kept explaining the same five formats to the same confused people. This is the short version.
The formats you'll actually meet
| Format | One-liner | Use it when |
|---|---|---|
| Shapefile | The immortal fossil | A counterpart demands it |
| GeoJSON | JSON with coordinates | Web maps, APIs, small data |
| GeoPackage | SQLite with superpowers | Almost everything else |
| KML | Google Earth's love letter | Presentations, fieldwork |
| GeoTIFF | Pixels with a location | Rasters: elevation, imagery |
Three rules of thumb
1. When in doubt, GeoPackage. One file, real data types, handles both
vectors and rasters, no 2 GB limit, no .shp/.shx/.dbf/.prj scavenger hunt.
It's been the sensible default for a decade.
2. GeoJSON for the web, but mind the size. It's text, it's readable, every mapping library eats it happily. It's also 5–10× larger than binary formats — past a few megabytes, tile it or move on.
3. Never trust a file without a CRS. Half of all GIS support questions are a
missing or wrong coordinate reference system. If your data lands in the Gulf of
Guinea (latitude 0, longitude 0 — a place GIS people know as Null Island), you
didn't lose your data. You lost your .prj.
Why property people should care
Property management is quietly full of geodata: cadastral boundaries, utility easements, drainage, snow-removal contracts, fire hydrant positions. That data arrives in whatever format the municipality, surveyor or contractor happened to export — and it's worth exactly nothing if nobody in your organisation can open it.
You don't need a GIS department. You need to know what you've been sent, whether it's intact, and how to convert it into something your tools understand. That's a solved problem — sometimes with a browser tab, sometimes with one email to someone who does this daily.
We're that someone. Say hello.