# Possible to geocode from file using GMT?

**URL:** <https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105>\
**Category:** Geo\
**Created:** [January 16, 2026, 10:52pm UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105 "2026-01-16T22:52:13Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![mihalybaci](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mihalybaci/32/13528_2.png) [@mihalybaci](https://discourse.julialang.org/u/mihalybaci)\
**Post date:** [January 16, 2026, 10:52pm UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105/1 "2026-01-16T22:52:13Z")

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I am looking to gecode some address information (convert addresses to lon/lat pairs). I found the `geodcode` function in GMT.jl, and it looks simple enough. But, is it possible to avoid sending the addresses to a web service and download an OpenStreetMap dataset for a region and use that file instead?

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**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [January 17, 2026, 12:01am UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105/2 "2026-01-17T00:01:38Z")

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Sorry, don’t understand the question. Yes the GMT’s [geocoder](https://www.generic-mapping-tools.org/GMTjl_doc/documentation/utilities/geocoder.html) uses a free web service with an access provided via GDAL and you cannot use it without that service. I also don’t understand the reference to OpenStreetMap. It’s not used at all.

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**Author:** ![mihalybaci](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mihalybaci/32/13528_2.png) [@mihalybaci](https://discourse.julialang.org/u/mihalybaci)\
**Post date:** [January 17, 2026, 1:08am UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105/3 "2026-01-17T01:08:26Z")

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Yeah, I think I worded my question poorly. The OSM piece was just that the webservice used is OSM\_NOMINATIM, so that’s where that came from but is beside the point.

Really my concern is more about feeding addresses into a web service and the possible privacy issues that may create. So I was hoping to be able to download a dataset (from nominatim) and point the `geocode` function to the one I have on disk. It’s a not a big deal, but I think it would be preferable.

edit: I found the instructions on the nominatim website, and it seems a bit intense, so I think I can just stick with the web service.

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**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [January 17, 2026, 1:34am UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105/4 "2026-01-17T01:34:19Z")

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Ah, I had forgotten the service name.

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**Author:** ![juliohm](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/juliohm/32/215266_2.png) [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Post date:** [January 17, 2026, 2:58am UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105/5 "2026-01-17T02:58:20Z")

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Related:

> [@ANN: OSMGeocoder.jl](https://discourse.julialang.org/t/ann-osmgeocoder-jl/133478):
>
> Announcing [OSMGeocoder.jl](https://github.com/joshday/OSMGeocoder.jl)! This package enables geocoding through OpenStreetMap’s Nominatim API. Searches are cached in a SQLite database stored in your scratch space. It is already available in the general registry. Enjoy!

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**Author:** ![mihalybaci](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mihalybaci/32/13528_2.png) [@mihalybaci](https://discourse.julialang.org/u/mihalybaci)\
**Post date:** [January 18, 2026, 1:51am UTC](https://discourse.julialang.org/t/possible-to-geocode-from-file-using-gmt/135105/6 "2026-01-18T01:51:08Z")

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Oh yeah, I saw that one too as an option!