GIS Blog
Practical, technically honest writing on GIS file formats, conversions, coordinate systems, and the open-source mapping stack. Every article is hand-written from working GIS practice.
Where to Get Free Geospatial Data: 10 Sources Every GIS User Should Know
Ten free, well-maintained sources for vector, raster, and tabular geospatial data. Every entry with format, download path, and the kind of project it fits.
How to Export PostGIS Data to GeoJSON: 4 Methods Compared
PostGIS is where serious spatial data lives; GeoJSON is where the web reads it. Four reliable bridges, with code examples and the trade-offs spelled out.
GIS File Format Comparison Table 2025
Ten GIS vector formats, seven axes of comparison, one table. The reference to pin next to your desk for the next time someone asks 'which format should we use?'
How to Convert KML to GeoJSON: QGIS, ogr2ogr, and Browser Tools
KML is everywhere Google Earth has been; GeoJSON is what every web map reads natively. Three reliable conversion paths, and the things that quietly drop on the way.
GML Explained: The XML-Based GIS Format Used by Governments
If you've ever downloaded cadastral data from a European government portal and stared at gigabytes of XML, you've met GML. Here's why governments love it and how to extract useful data from it.
GIS File Format Comparison: The Complete 2025 Table
Eleven GIS formats, six axes of comparison, one table. The reference you can come back to next time someone asks 'which format should we use?'
How to Validate GIS Files Before Importing into QGIS
Most QGIS import failures have nothing to do with QGIS. They're caused by malformed GIS files that you can catch in 30 seconds with the right validation step.
ogr2ogr Cheat Sheet: The 20 Commands Every GIS User Needs
Ninety percent of practical GIS data work is reachable with twenty ogr2ogr incantations. Here they are, with the flags explained.
How to Export PostGIS Data to GeoJSON: 4 Methods Compared
PostGIS is where serious spatial data lives. GeoJSON is where the web reads it. Four reliable ways to bridge them, with the trade-offs spelled out.
Why Shapefile Is Still Everywhere (And Why That's a Problem)
Shapefile is the cockroach of GIS formats — it survives every extinction event. Here's a clear-eyed look at the constraints it still imposes on real projects, and the moment it becomes a liability.
How to Convert Shapefile to GeoJSON: Complete Guide
A working guide to Shapefile-to-GeoJSON conversion using QGIS, the GDAL command line, and a browser. Includes the encoding and CRS pitfalls that bite first-time users.
WGS84 vs UTM vs Web Mercator: CRS Explained for GIS Beginners
The earth is a lumpy ellipsoid; maps are flat. Coordinate reference systems mediate that mismatch. Here's the primer for the three you'll meet most.
GeoJSON vs Shapefile: Which Format Should You Use in 2025?
Both formats have survived for decades, but they solve different problems. Here's how to choose between them in 2025 — and why "just use whichever" is the wrong answer.
GeoJSON Coordinate Precision: How Many Decimal Places Do You Really Need?
Most GeoJSON files carry coordinates with 14 decimal places — sub-nanometer precision for a planet with continental drift. Here's how to cut precision without losing anything that matters.
Top 10 Free GIS Tools for Beginners in 2025
There's never been a better time to learn GIS without spending a cent on software. Here are the ten free tools that cover the entire workflow — from data wrangling to publishing maps on the web.
KML vs GeoJSON: Which is Better for Web Maps?
Both formats can show a point on a map, but they make wildly different trade-offs. Here's when KML wins, when GeoJSON wins, and why most web maps should use GeoJSON.
GeoPackage vs Shapefile: A Developer's Migration Guide
GeoPackage solves almost every Shapefile shortcoming. So why is Shapefile still the default in 2025? The honest answer, and a migration recipe.
What is GeoPackage and Why Is It Replacing Shapefile?
GeoPackage looks like a 'just one more file format' but it's actually a portable SQLite database. Here's why QGIS made it the default, and the technical details that matter.
How to Convert KML to GeoJSON: QGIS, ogr2ogr, and Online Tools
KML is the Google Earth export everyone has and GeoJSON is the web map everyone uses. Three reliable ways to bridge them — and what gets quietly dropped on the way.
WGS84 vs UTM vs Web Mercator: CRS Explained for GIS Beginners
The earth is a lumpy ellipsoid and maps are flat. Coordinate reference systems negotiate that mismatch — here's how the three you'll meet most often work.
Understanding Coordinate Reference Systems: WGS84, UTM, and More
If your map looks stretched, your distances are wrong, or your data appears in the wrong ocean, the cause is almost always a CRS problem. Here's what you need to know.