For each example in this post, I will be linking to the sea otter pools at the Vancouver aquarium. That location has the coordinates of 49.30063,-123.13149
To link to it, you would use ‘geo:49.30063,-123.13149’.
Depending on your web browser, pasting that into the search bar might prompt you to select which map website you want to use to view that location. For me in Firefox, it asked me to pick between Google Maps and OpenStreetMaps. It’s even more convenient on mobile, where it asks me which map app I want to open it with. Both CoMaps and Google Maps handled it correctly.
If you are writing a post or comment on Lemmy/Piefed/etc., you can place it in the second part of the markdown link format: [Sea Otter Pools](geo:49.30063,-123.13149). This would output like this: Sea Otter Pools
The linked OpenStreetMap wiki page has a good summary of how well various apps support this scheme. A lot of people here are active in the open source space, so please consider following up with the apps that are currently missing support or have partial support for this: https://wiki.openstreetmap.org/wiki/Geo_URI_scheme
EDIT: I forgot to mention, you can also use apps like this one to convert maps links between each other
https://github.com/jakubvalenta/GeoShare
https://f-droid.org/packages/page.ooooo.geoshare/
https://apt.izzysoft.de/fdroid/index/apk/page.ooooo.geoshare
Is this better than What Three Words which also has a URL scheme? And is more memorable.
The geo URL scheme works even for non English speakers and it won’t give you a location on the other side of the world if you lake a typo or pronounce it bad.
Since WhatThreeWords is proprietary, it likely won’t be as easy to get it implemented in everything. I think the difficulty with coordinates can be solved by having an easy way to copy the Geo URI from various map apps