Tags: geo

Yesterday when I mentioned my paranoia of third-party dependencies on The Session, I said:

I’ve built in the option to switch between multiple geocoding providers. When one of them inevitably starts enshittifying their service, I can quickly move on to another. It’s like having a “go bag” for geocoding.

(Geocoding, by the way, is when you provide a human-readable address and get back latitude and longitude coordinates.)

My paranoia is well-founded. I’ve been using Google’s geocoding API, which is changing its pricing model from next March.

You wouldn’t know it from the breathlessly excited emails they’ve been sending about it, but this is not a good change for me. I don’t do that much geocoding on The Session—around 13,000 or 14,000 requests a month. With the new pricing model that’ll be around $15 to $20 a month. Currently I slip by under the radar with the free tier.

So it might be time for me to flip that switch in my code. But which geocoding provider should I use?

There are plenty of slop-like listicles out there enumerating the various providers, but they’re mostly just regurgitating the marketing blurbs from the provider websites. What I need is more like a test kitchen.

Here’s what I did…

I took a representative sample of six recent additions to the sessions section of thesession.org. These examples represent places in the USA, Ireland, England, Scotland, Northern Ireland, and Spain, so a reasonable spread.

For each one of those sessions, I’m taking:

• the venue name,
• the town name,
• the area name, and
• the country.

I’m deliberately not including the street address. Quite often people don’t bother including this information so I want to see how well the geocoding APIs cope without it.

I’ve scored the results on a simple scale of good, so-so, and just plain wrong.

• A good result gets a score of one. This is when the result gives back an accurate street-level result.
• A so-so result gets a score of zero. This when it’s got the right coordinates for the town, but no more than that.
• A wrong result gets a score of minus one. This is when the result is like something from a large language model: very confident but untethered from reality, like claiming the address is in a completely different country. Being wrong is worse than being vague, hence the difference in scoring.

Then I tot up those results for an overall score for each provider.

When I tried my six examples with twelve different geocoding providers, these were the results:

Geocoding providers

Provider	USA	England	Ireland	Spain	Scotland	Northern Ireland	Total
Google	1	1	1	1	1	1	7
Mapquest	1	1	1	1	1	1	7
Geoapify	0	1	1	0	1	0	3
Here	1	1	0	1	0	0	3
Mapbox	1	1	0	1	1	-1	3
Bing	1	0	0	0	0	0	1
Nominatim	0	0	0	0	-1	1	0
OpenCage	-1	1	0	0	0	-1	-1
Tom Tom	-1	-1	0	0	-1	1	-2
Positionstack	0	-1	0	-1	1	-1	-2
Locationiq	-1	0	-1	0	0	-1	-3
Map Maker	-1	0	-1	-1	-1	-1	-5

Some interesting results there. I was surprised by how crap Bing is. I was also expecting better results from Mapbox.

Most interesting for me, Mapquest is right up there with Google.

So now that I’ve got a good scoring system, my next question is around pricing. If Google and Mapquest are roughly comparable in terms of accuracy, how would the pricing work out for each of them?

Let’s say I make 15,000 API requests a month. Under Google’s new pricing plan, that works out at $25. Not bad.

But if I’ve understood Mapquest’s pricing correctly, I reckon I’ll just squeek in under the free tier.

Looks like I’m flipping the switch to Mapquest.

If you’re shopping around for geocoding providers, I hope this is useful to you. But I don’t think you should just look at my results; they’re very specific to my needs. Come up with your own representative sample of tests and try putting the providers through their paces with your data.

If, for some reason, you want to see the terrible PHP code I’m using for geocoding on The Session, here it is.

The Session has been online for over 20 years. When you maintain a site for that long, you don’t want to be relying on third parties—it’s only a matter of time until they’re no longer around.

Some third party APIs are unavoidable. The Session has maps for sessions and other events. When people add a new entry, they provide the address but then I need to get the latitude and longitude. So I have to use a third-party geocoding API.

My code is like a lesson in paranoia: I’ve built in the option to switch between multiple geocoding providers. When one of them inevitably starts enshittifying their service, I can quickly move on to another. It’s like having a “go bag” for geocoding.

Things are better on the client side. I’m using other people’s JavaScript libraries—like the brilliant abcjs—but at least I can self-host them.

I’m using Leaflet for embedding maps. It’s a great little library built on top of Open Street Map data.

A little while back I linked to a new project called OpenFreeMap. It’s a mapping provider where you even have the option of hosting the tiles yourself!

For now, I’m not self-hosting my map tiles (yet!), but I did want to switch to OpenFreeMap’s tiles. They’re vector-based rather than bitmap, so they’re lovely and crisp.

But there’s an issue.

I can use OpenFreeMap with Leaflet, but to do that I also have to use the MapLibre GL library. But whereas Leaflet is 148K of JavaScript, MapLibre GL is 800K! Yowzers!

That’s mahoosive by the standards of The Session’s performance budget. I’m not sure the loveliness of the vector maps is worth increasing the JavaScript payload by so much.

But this doesn’t have to be an either/or decision. I can use progressive enhancement to get the best of both worlds.

If you land straight on a map page on The Session for the first time, you’ll get the old-fashioned bitmap map tiles. There’s no MapLibre code.

But if you browse around The Session and then arrive on a map page, you’ll get the lovely vector maps.

Here’s what’s happening…

The maps are embedded using an HTML web component called embed-map. The fallback is a static image between the opening and closing tags. The web component then loads up Leaflet.

Here’s where the enhancement comes in. When the web component is initiated (in its connectedCallback method), it uses the Cache API to see if MapLibre has been stored in a cache. If it has, it loads that library:

caches.match('/path/to/maplibre-gl.js')
.then( responseFromCache => {
    if (responseFromCache) {
        // load maplibre-gl.js
    }
});

Then when it comes to drawing the map, I can check for the existence of the maplibreGL object. If it exists, I can use OpenFreeMap tiles. Otherwise I use the old Leaflet tiles.

But how does the MapLibre library end up in a cache? That’s thanks to the service worker script.

During the service worker’s install event, I give it a list of static files to cache: CSS, JavaScript, and so on. That includes third-party libraries like abcjs, Leaflet, and now MapLibre GL.

Crucially this caching happens off the main thread. It happens in the background and it won’t slow down the loading of whatever page is currently being displayed.

That’s it. If the service worker installation works as planned, you’ll get the nice new vector maps. If anything goes wrong, you’ll get the older version.

By the way, it’s always a good idea to use a service worker and the Cache API to store your JavaScript files. As you know, JavaScript is unduly expensive to performance; not only does the JavaScript file have to be downloaded, it then has to be parsed and compiled. But JavaScript stored in a cache during a service worker’s install event is already parsed and compiled.

OpenFreeMap

This project, based on OpenStreetMap, looks great:

OpenFreeMap lets you display custom maps on your website and apps for free.

You can either self-host or use our public instance.

I’m going to try it out on The Session once there’s documentation for using this with Leaflet.

The Gods of Logic, by Benjamín Labatut

Benjamín Labatut draws a line from the Vedas to George Boole and Claude Shannon onward to Geoffrey Hinton and Frank Herbert’s Butlerian Jihad.

In the coming years, as people armed with AI continue making the world faster, stranger, and more chaotic, we should do all we can to prevent these systems from giving more and more power to the few who can build them.

A microdata enhanced HTML Webcomponent for Leaflet | k-nut — Blog

Here’s a nice HTML web component that uses structured data in the markup to populate a Leaflet map.

Personally I’d probably use microformats rather than microdata, but the princple is the same: progressive enhancement from plain old HTML to an interactive map.

Our Maps Don’t Know Where You Are – The Markup

I wish more publishers and services took this approach to evaluating technology:

We scrutinize third-party services before including them in our articles or elsewhere on our site. Many include trackers or analytics that would collect data on our readers. These may be standard across much of the web, but we don’t use them.

404 Page Not Found | Kate Wagner

Considering the average website is less than ten years old, that old warning from your parents that says to “be careful what you post online because it’ll be there forever” is like the story your dad told you about chocolate milk coming from brown cows, a well-meant farce. On the contrary, librarians and archivists have implored us for years to be wary of the impermanence of digital media; when a website, especially one that invites mass participation, goes offline or executes a huge dump of its data and resources, it’s as if a smallish Library of Alexandria has been burned to the ground. Except unlike the burning of such a library, when a website folds, the ensuing commentary from tech blogs asks only why the company folded, or why a startup wasn’t profitable. Ignored is the scope and species of the lost material, or what it might have meant to the scant few who are left to salvage the digital wreck.

Misconceptions

Some common geographic mental misplacements.

Days Since Incident

I love this list of ever-increasing timelines. All that’s missing is the time since the Carrington Event, just to remind us what could happen when the next one hits.

Pizza Exchange Rate | FlowingData

This is a story about pizza and geometry.

The interactive widget here really demonstrates the difference between showing and telling.

home sweet homepage

I can’t remember the last time that a website made me smile like this.

Globle

Like Wordle, but for geography instead of words.

Every day, there is a new Mystery Country. Your goal is to guess the mystery country using the fewest number of guesses. Each incorrect guess will appear on the globe with a colour indicating how close it is to the Mystery Country.

Space Elevators: How a sci-fi dream could be built today

Surveying the current practical and theoretical factors for and against space elevators (including partial elevators—skyhooks!).

How Yahoo Became an Internet Villain - The Atlantic

Andy, Jason, and Maciej testify against Yahoo.

Time Lords | Lapham’s Quarterly

A fascinating look at the history of calendrical warfare.

From the very beginning, standardized global time zones were used as a means of demonstrating power. (They all revolve around the British empire’s GMT, after all.) A particularly striking example of this happened in Ireland. In 1880, when the United Kingdom of Great Britain and Ireland declared GMT the official time zone for all of Great Britain, Ireland was given its own time zone. Dublin Mean Time was twenty-five minutes behind GMT, in accordance with the island’s solar time. But in the aftermath of the 1916 Easter Rising, London’s House of Commons abolished the uniquely Irish time zone, folding Ireland into GMT, where it remains to this day.

An Ocean of Books

What you see is the big map of a sea of literature, one where each island represents a single author, and each city represents a book. The map represents a selection of 113 008 authors and 145 162 books.

This is a poetic experiment where we hope you will get lost for a while.

Mapping a World of Cities

A timeline of city maps, from 1524 to 1930.

Project Orbital Ring

An Orbital Ring System as an alternative to a space elevator.

Representing nothing short of the most ambitious project in the history of space exploration and exploitation, the Orbital Ring System is more or less what you would imagine it to be, a gargantuan metal ring high above the Earth, spanning the length of its 40,000 kilometer-long diameter.

Spatial Awareness

Robin Hawkes has made a lovely website to go with his newsletter all about maps and spatial goodies.

geoTrad - Google My Maps

Well, this is a rather wonderful mashup made with data from thesession.org:

The distribution of Irish traditional tunes which reference place names in Ireland