Geocoding & addresses
Turning address text into coordinates, and coordinates back into places — with the match quality attached.
Geocoding is the one operation on this site that always succeeds. Give a geocoder a street that does not exist and it will return a coordinate for the town; give it a typo and it will return its best guess. The latitude and longitude come back with the same number of decimal places either way, so precision in the output tells you nothing about accuracy.
That makes match quality the whole subject. Every serious geocoder reports what it actually matched — a rooftop, an interpolated point along a street, or the centroid of a locality — and the difference between those is three orders of magnitude on the ground. Carrying that field through to the output is what separates a geocoded dataset you can join on from one you cannot.
Below: the concepts cover how geocoders work and what the match levels mean, the how-to guides cover batch geocoding, reverse geocoding and cleaning address text before you send it, and the fixes are the specific ways a batch comes back wrong.
🧭 Start with the concepts
The ideas the how-to guides below assume you already have.
- Geocoding Explained: From an Address String to a Coordinate
- The Address Data Model: Why an Address Is Not a String
- Choosing a Geocoder: Coverage, Licence and Cost Compared
- Match Quality Explained: Reading a Geocoder's Confidence Score
- Rooftop, Interpolated or Centroid: Geocoding Precision Levels
- Address Matching Explained: Why Exact String Equality Fails
⚙️ Then do the task
Step-by-step walkthroughs with code you can copy and adapt.
- How to Fuzzy-Match Place Names When Joining Spatial Data in Python
- How to Geocode Addresses in Python
- How to Parse and Normalise Addresses in Python
- How to Geocode with Nominatim from Python Without Being Blocked
- How to Batch Geocode Thousands of Addresses in Python
- How to Cache Geocoding Results So a Rerun Costs Nothing
Show every how-to guide in this topic
🔧 When it breaks
The errors this topic produces, with the cause explained rather than just the command.
Learning paths through this topic
A curated route rather than a list — the guides in the order that builds on itself.
Related topics
Subjects that keep coming up alongside this one, most overlap first.