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Comment by simonw | Hacker News Reader

I just used their pmtiles tool to grab a map of just the area around Half Moon Bay, south of San Francisco.

I grabbed the latest macOS Go binary from https://github.com/protomaps/go-pmtiles/releases

I found a rough bounding box using http://bboxfinder.com/#37.373977,-122.593346,37.570977,-122....

Then I ran this:

    pmtiles extract https://build.protomaps.com/20231023.pmtiles hmb.pmtiles \
      --bbox=-122.593346,37.373977,-122.400055,37.570977

The result was a 2MB hmb.pmtiles file which, when dragged onto the "drop zone" on https://maps.protomaps.com/ showed me a detailed zoomable map, with full OpenStreetMap metadata (airport polygons etc) - all the way down to individual building outlines level.

All that in 2MB! I'm really impressed.

My file is here: https://gist.githubusercontent.com/simonw/3c1a5358ca8f782f13...

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I turned this into a demo: https://simonw.github.io/hmb-map/ and a blog post: https://til.simonwillison.net/gis/pmtiles

Beat me to it. I was working on this last night but had to sleep before writing it up. I was trying to use parcel as a bundler and was thrown because whatever dev server it uses doesn't seem to support HTTP range requests properly. I was getting "invalid magic number" on the client side.

That's really cool. Cloud be really use full for local businesses. They often embed Google maps, but I feels like having a map from the local are would be sufficient, and cheaper.

Wouldn’t they need to keep updating this from time to time to stay current? That would likely kill any savings pretty quickly.

It depends what you use it for. I plan to use it for blog posts where I show the track of where I walked. I actually like that the map won't update. It wouldn't make sense to show me walking across a map of the future, would it? It's a record of the past and the map should be frozen just like the writing.

Sure, but in GP's context of local businesses, they certainly will want to keep up-to-date with any changes to make sure customers can still find them.

Yes, absolutely. I think, in that case, a managed tileserver (using PMTiles or otherwise) is probably the best solution.

Protomaps generates daily world files I believe [1] but I haven't confirmed that they're used by the download tool yet. In theory you can download the data everyday to pick up updates.

[1] https://maps.protomaps.com/builds/

Edit: re-reading top comment it looks like they're using a daily file so you'd just have to create a cron job

I did the same and got a map of Gran Canaria which is 15MB! And it's not like a user is ever going to download the entire file. It's really quite cool and I'm quite excited to put maps on my static site.

I realise this isn't tech support but I have no idea why it doesn't work for me. The pmtile file you linked works, but creating my own smaller one doesn't.

But the concept is great to get a map for a project

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