We publish a geocoding service using ArcGIS server but are interested in moving to a free and open source alternative but can't seem to find anything that allows us to use local address data. Are there any geolocators that are both free open source and have the ability to utilize local data? The alternatives that I've evaluated (including those mentioned here) are either not free or don't support the use of local data:

  • TIGER geocoder for PostGIS: built primarily for TIGER features and address ranges. Can't really find any documentation on how to modify it to incorporate local data instead of TIGER data
  • Geocommons: Free and open source, but doesn't accept local data
  • Geocode.xyz: Same issues as Geocommons
  • Gisgraphy: Only accepts OSM and GeoNames data
  • Mapzen/Pelias: Free up to 25K requests/month; doesn't support local data
  • Photon: Same issues as Mapzen
  • The question that you are asking here seeks a list of answers, which makes it too broad for focused Q&A.
    – PolyGeo
    Dec 12 '17 at 21:47
  • 1
    I don't think that it's asking for a list of answers, just whether there is a geolocator that is 1) free and open source, and 2) able to utilize local data. I've also linked to another post that addresses a similar question but has a slightly different objective.
    – neighdough
    Dec 12 '17 at 22:24
  • Thank you for drawing my attention to that earlier Q&A which has now been converted to Community Wiki, and wiki-locked, because it too seeks a list of answers. Software recommendations can always be sought at the Software Recommendations Stack Exchange and if you prefer to ask them of GIS experts then the GIS Chat Room is always open.
    – PolyGeo
    Dec 12 '17 at 22:44

You should definitely look closer at the Mapzen Pelias geocoder.

We have been having this same issue for several years, and recently discovered that one of the back-end sources for Pelias is OpenAddresses.io.

You can examine the back-end data sources broken down by State and City here:


And if your city/region isn't covered and there is data available, I would recommend contributing a source.

Emails from the openaddresses.io folks let me know that they are refreshing the sources on a weekly basis, and that Pelias/Mapzen is refreshing every 2 weeks or so.

For Denver, and for DPS, this is a big deal, and we plan on implementing it in the new year. This system is far more up-to-date than Google, ESRI, etc. and more accurate.

Python implementation couldn't be easier, and you have lots of flexibility to get at the back-end results:


For us, this means we can read address data from our student information system, geocode via Mapzen, and attach the lat/lon to the addressID, then built geometry using PostGIS.

And regarding pricing, if you need more than 25k/month, I would say their pricing plan is very cheap: https://mapzen.com/pricing/

  • Thanks for pointing that out. I took a look and they're already consuming some of the local data that we use to build our locators, but there's still an issue with cost. We routinely get data with over 1 million records and their pricing model means that we would have to pay around $500 to process that, which in a pinch we could do, but would definitely prefer a solution that was completely free.
    – neighdough
    Dec 12 '17 at 20:27
  • I don't think anyone is going to give that away for free, and there doesn't seem to be a better way, even with paid software like ESRI, to get better results. Dec 12 '17 at 20:29
  • govtech.com/biz/…
    – PolyGeo
    Jan 3 '18 at 9:12

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