MapLibre Tile: a modern and efficient vector tile format | Hacker News Reader

MapLibre Tile: a modern and efficient vector tile format

maplibre.org

432 pointstodsacerdoti92 comments

Come to the MapLibre talk in the Geospatial devroom at FOSDEM on Saturday

https://fosdem.org/2026/schedule/event/QAL9VN-state-of-the-m...

If one can fit :P

Had to search a bit, but here's a demo page: https://maplibre.org/maplibre-gl-js/docs/examples/display-a-... Can be compared with: https://maplibre.org/maplibre-gl-js/docs/examples/display-a-...

In that example I saw this in the console:

    before - 2.41+26.29+24.87+71.28+59.2+77.57 - 261.62kb
    after  - 2.45+22.4 +22.66+60.6+51.99+77.57 - 237.67kb

So roughly a ~10% compression improvement, neat!

Note that the demotiles style is not really comparable to a production basemap such as ones based on the popular OpenMapTiles schema. The article linked in the announcement has some more findings related to compression ratio.

Also note that lightweight encodings are built into the format, and different tiles can even be encoded in a completely different way. So you have to use heuristics to find the best combination of encodings and often you need to make a trade off between tile size and decoding performance. It is still early days for MLT, but all this means there are a lot of possibilities for optimization. In fact, AWS is again financing work on MLT this year, with a focus on optimization.

Lastly, when benchmarking tile size, it is good to look at actual usage patterns instead of size of the total tile set. Nobody is zooming into a random spot in the ocean, for example. ;-)

This is interesting. We recently deployed a solution that uses pmtiles and it's great.

https://docs.protomaps.com/pmtiles/

afaik, pmtiles uses mvt, let's hope the tooling to convert the tiles to mlt also becomes available.

Oh pmtiles is such a simple and innovative solution!

Yes, Absolutely in love with it. Loading tiles with range requests made our application so much faster.

It's very cool! If you want to get higher cache hit rates from a CDN or redis etc. and lower the amount of S3 reads, you can get set up a proxy to convert `/{z}/{x}/{y}.mvt` requests into the byte-range requests: https://docs.protomaps.com/deploy/

Brandon has some example code you can lift to dump it into a Cloudflare Worker or other platforms on that page.

Thank you. I'm going to try this on a different project that we have. Our current deployment is designed to work directly through s3/api gateway which reduces the number of moving parts.

We update the tiles frequently, so the setup has been amazing for us.

It is. I’ve found it so useful I created an Elixir library to act as a cache in front on a pmtiles file. https://hex.pm/packages/ex_pmtiles

PMTiles is actually pretty agnostic to what kind of tiles it contains! There is already a PMTiles PR that updates the byte that specifies the type of tile to include MLT.

https://github.com/protomaps/PMTiles/pull/596

Oh wow, thank you, looking forward to this

Neat, as someone integrating PMTiles right now, thank you!

PMtiles is often used with MVT tiles, but it can encapsulate a variety of tile types: the current spec [1] has defined tile types for MVT, PNG, JPEG, WebP and AVIF (plus "Unknown/Other").

[1]: https://github.com/protomaps/PMTiles/blob/main/spec/v3/spec....

Absolutely, we have MVT tiles at the moment, I'm hoping to test MLT soon

I'm building PMTiles through Tilemaker, PMTiles is incredible, but sadly it will take a lot of work to produce MLT though Tilemaker :/

MapLibre is an awesome project, their JS library is by far the best way to display maps in the browser that I've come across. Very excited to eventually switch to this format!

This 100%

Planetiler currently supports generating MLT by adding —-tile-format=mlt cli argument. It’s only on latest main right now but I should be able to get a release out in the next few days. In my testing I’ve seen ~10% reduction in overall OpenMapTiles archive size with default settings but there are some more optimizations the team is working on that should bring it down even further.

Unfortunately, Tilemaker hasn't planned or cannot plan to support MLT in the medium-term.

That will leave a significant part of the community out of this transition.

See this interesting (and quite heated) discussion : https://github.com/systemed/tilemaker/issues/856

You can always convert after the fact. Just go from MVT to MLT. There's a Java based program in the repo.

How much times would it take ? Generating the planet with Tilemaker takes 2 hours on an enormous 350 Go RAM server.

It's cool that stuff like vector file formats is still being reinvented. What's the new idea(s) here, though?

Like, I get that it's new and has better features (better compression, faster decoding, etc.) --- but what are the new ideas or insights that led to this design?

Does anyone self host maps? If you do, mind sharing the pros, cons and tools to do that?

We've been self-hosting protomaps (aka pmtiles) for several years. The only thing you need server-side is a web server that can serve static files and supports range requests (so anything works; I've tried caddy and nginx). The map is one large file, it's easy to share it between however many servers you need.

https://docs.protomaps.com/guide/getting-started

Downsides? Nothing major that I can think of. You have to add another client-side dependency (support for their custom protocol); the library is pretty small and easy to audit.

Editing map styles is slightly more difficult because generic maplibre styles won't work with it: they add a bit of custom sauce on top. IIRC this editor worked fine, you can import one of protomaps styles and base your work off it:

https://maputnik.github.io/editor

That's probably it.

Are the names of cities/streets included in the tiles, or do they have to be placed from a different data source?

No, the names are there in the file, streets included. Their default styles did not support the languages we needed out of the box (everything was shown in the local language or English IIRC), but it was easy to fix by patching the style. I don't remember the exact fix, but it was about as simple as replacing something like `["get", "name_en"]` with `["get", ["coalesce", "name_xx", "name_en"]]`.

Is there enough information to show exact addresses? For example "221B Baker Street"

Sure. You can look at their demo, it uses the exact same single-file hosting mechanism (the network requests tab in the browser dev tools confirms it — it doesn't send any other requests), and street/house addresses are visible on the map.

https://maps.protomaps.com

How do you update pmiles? Do you have to rebuild the entire map every time? If so, I think that's a downside/limitation for some use cases.

Don't know about pmtiles specifically, but on tile servers I've used it's possible to update administrative regions separately.

We use mod_tile+renderd: https://github.com/openstreetmap/mod_tile

In short: We have a script that builds a pbf of the area we are interested in (Colorado, USA) from OSM, then set up a openstreetmap-tile-server container with that data, bring in our styles, and then set up renderd.

I do. The pros are hosting own data and have total control over stack and cloud hosting. The cons are having to code your own stack and do cloud management. I use PostGis to storage and serve vector tiles. And I use a simple backend with AWS S3 to store and serve raster data (GeoTiff COG).

Respect this commitment. I think to be honest I'd only ever consider hosting a tile server if I was actually rendering data on the tiles or there was something 'special' about them (e.g style). Using $whatever hosted tiles are likely to be faster for the user as they'll be cached, served statically.

I am hosting user data from the database. It is very easy with this stack: - PostgreSQL with PostGIS - Django with MVT-tiles plugin - MapLibre

I had to go down this path for a print-on-demand book project. If you need high-DPI assets for physical print the commercial static map APIs are prohibitively expensive or restrict usage rights for resale. Self-hosting was basically the only way to generate 300dpi rasters at scale without destroying the margins.

Have used pmtiles to self-host a “find your nearest store” map, which only needed to cover Australia. Created two sources: (1) a low-detail worldwide map to fill out the view (about 50 MB), and (2) a medium-to-high detail source for Australia only, up to zoom level 15 (about 900 MB). In this case, there’s no need for up-to-date maps, so we were able to upload these two files to S3 and forget about them. Works great!

I am not familiar with the ecosystem of geographic data and mapping as online services. Can someone please explain...

* How this tile format, or the organization behind it, related to OpenStreetMap (if it is related at all)?

* Why the need to replace the previous tile format / scheme which they mention?

* What challenges such a project faces (other than, I suppose, being noticed and considered for adoption)?

1) It's not. Maplibre is a JS library for displaying map data. OpenStreetMap is a collection of map data that is published in various formats. Different levels of the stack.

2) It's an optimization/advancement. There are some pain points in the older version that 10 years of experience can fix in a newer format.

3) Attention, funding. Technically, they're at the leading edge of open source.

Additionally to point 2, the older format was created by a company (Mapbox) that used to be open source-friendly but has recently made a larger pushback against open source and open standards, changing the licenses of much of their formerly open source work. (The Maplibre JS library itself is a fork of that company's previous open source work from its last open source drop to keep the work open source.)

> There are some pain points in the older version that 10 years of experience can fix in a newer format.

What were the major pain points? Compression ratio and speed seem like two of them. (Thanks for answering the elementary questions.)

Lack of tessellation was a big one. In many cases you'd rather have the polygons pre-tessellated in the file format. Now you can. Or you can avoid doing that and save the bytes.

The format is also designed to slide onto the GPU more easily. If you're writing a vector map from scratch, I say just do MLT.

There was never any support for more complex geometry. Now someone could add curves.

Attributes had to be fairly simple. Now you could conceivably do hierarchical attributes.

The requirements for navigation data tiles get specific and weird (from a visual perspective). Now it can be added without breaking existing data.

Thanks, @wirefool :-)

> OpenStreetMap is a collection of map data that is published in various formats.

So, OpenStreetMap.org is just one site which uses the "real" OpenStreetMap, which is the data?

The data can be downloaded here: https://planet.osm.org/ Here's a list of OSM data users: https://wiki.openstreetmap.org/wiki/List_of_OSM-based_servic...

The key info token you'll want to know as someone foreign to map topics is that maplibre is a licence continuity fork of the formerly open source Mapbox code.

Everything else pretty much derives from this, e.g. yeah, OSM did not suddenly go all in on former mapbox stuff only because the company started keeping updates behind a paywall, OSM continues to be as tool-agnostic as ever.

Looks great. I wish there was similar advancement for full 3d tiles. The only real option at the moment is cesiums 3d tiles format which is nowhere near as fast as it could/should be

I <3 Martin and the team that built it. It's great to see that the Rust stack they used is the one I contributed to, now 8 years ago. Aging like fine wine!

"Modern" is such a silly way to advertise things.

Although the word is overused, hindsight can be a huge advantage in design.

It should be backed up, for sure. Like how is this modern?

In this case it's the column format for attributes and the newer encodings. Things the industry wasn't doing a decade ago.

We don't have a marketing department, so we're happy to take suggestions on our messaging!

What makes it modern are the ideas behind it: the column-oriented layout, support for lightweight encodings such as FSST and FastPFOR and support for pre-tessellation. Also, enabling doing more computations on the GPU instead of the CPU, which are made possible thanks to modern graphics APIs like Vulkan and Metal. I agree that it is better to be specific about these things (if that is your gripe with it), but there's only so many characters that fit into a title. ;)

Another thing worth mentioning is it's very similar to the structure of columnar formats like Arrow and Parquet. Anyone with familiarity with these formats could build a decoder in a couple of days. If they don't use FastPFOR.

I really wish they hadn't used FastPFOR. It's a research library and has an incredibly opaque algorithm:

https://ayende.com/blog/199523-C/integer-compression-underst...

FSST is similar in terms of underlying complexity. You need this complexity to get good performance though, it seems from the research.

If there were something better than FastPFOR, we would use it. If something comes up, we can always use a new tag and add it in the future.

There is still a lot to do, for example one can do like-operators on FSST without decompressing it.

Been following this for a little bit and am extremely excited for this. I think the final big hurdle for adoption (for those of use in the MapLibre stack at least) will be getting an equivalent As_MLT() function added to PostGIS.

and support in Geoserver

Unrelated, but I noticed that clicking the logo goes to the current permalink rather than the homepage, might be unintentional.

Thanks for the report. Should be fixed in a few hours once another of the project members approves https://github.com/maplibre/maplibre.github.io/pull/526

I just want support for globe view on maplibre native

Globe view is a large feature that would require dedicated engineering effort. Currently, we don’t have funding allocated for this feature.

If you or your organization would like to

- sponsor (-> https://maplibre.org/sponsors) the work or

- contribute engineering time (-> https://maplibre.org/community/), we’d be happy to discuss options.

Feel free to reach out on Slack (invite at https://slack.openstreetmap.us/).

All links in the top navigation are broken (404).

Sorry about that. Noticed the footnote was broken.

Fixed the footnote, broke all other links. Should be OK again when the caches catch up.

I find it shocking that a reputable resource such as this is still displaying the size of Greenland or Africa wrong (Mercator projection) in relation to other land masses in its marketing material and documentation, like here. It just brings doubt to the whole project, which is a shame considering all the time they must have put in. Why show the map that way when majority of its users will never use it for nautical navigation? https://maplibre.org/maplibre-gl-js/docs/examples/display-a-...

Accuracy where it matters is why. Do you have a better suggestion for projecting a sphere onto a rectangle?

I would not use such strong rhetoric as the GP, but I believe they probably mean we should lean towards using the Gall/Peters projection, which maintains lengths and areas, but not angles.

(There are of course other projections with other interesting features; or you could take the same projection but center the world differently etc.)

Web Mercator does not preserve angles.

We're currently forced to use a projection that is strictly worse than what it was based on, the Mercator projection, created in 1569.

Everyone on this thread needs to read this presentation entitled "Use Literally Anything But Web Mercator":

https://www.esri.com/content/dam/esrisites/en-us/events/conf...

Let's say that a bit louder shall we:

USE LITERALLY ANYTHING BUT WEB MERCATOR.

Thanks for that, I wasn't even aware that "web Mercator" was a thing.

Why? Why is lengths and areas more important than angles? You have to choose one, its essentially arbitrary. Personally I find it more useful to know what is parallel to what and what is at which angles from what, than some size. We have globes, so we know what the "real size" of Greenland looks like... this has always been a silly argument from the overzealous online looking for right wrongs that don't exist.

WEB MERCATOR DOES NOT PRESERVE ANGLES.

I know. But they mentioned Mercator, not Web Mercator.

They were talking about Web Mercator but didn’t know they were!

> Why is lengths and areas more important than angles?

Well, of course the answer is "it depends on what it is you want to learn from the map. If you're driving around and want to navigate, you'll take Mercator probably. But if you want to compare sizes of objects (like lakes or forests or islands or world states), especially when zoomed out, you'll prefer Gall-Peters.

Many argue, and I tend to agree, that when looking at a map of the whole world, you are typically better served with Gall-Peters in terms of what your interest is, and in fact, people _do_ use Mercator maps to semi-consciously compare sizes of things - and have false impressions about geo-politics because of it.

This comment is inaccurate! Web Mercator causes such large errors in geolocation that the NGA had to issue an advisory about it [1].

There is a whole science behind map projections and Google ignored it entirely when they created Web Mercator, which was a hack to divide the world into a quad tree. It was vaguely clever and utterly stupid at the same time.

[1] https://web.archive.org/web/20140607003201/http://earth-info...

> Accuracy where it matters is why

Why the downvotes for correcting this laughable statement? Web Mercator is well documented as being extremely inaccurate.

Hi - I understand you feel strongly; your Web Mercator input is interesting. I would just focus on the intellectually interesting part - people might not get it; you can't control that or compel them to.

You've been repeating essentially the same comment, writing in all caps (in some comments), complaining about downvotes, telling everyone they are idiots one way or another. None of those things are likely to be welcome.

Almost every commenter here repeated the same misconception, and I corrected them each time.

I feel justified in shouting in this case.

Web Mercator is the standard projection used on the web, if you think the we should use a different projection on the web then that's a completely separate argument

Because that's what everyone is used to.

Maplibre supports different projections if you want.

It's on our roadmap to support alternate projections, but as you can imagine it's a big project that so far nobody has been willing to pay for to implement unfortunately.

MapLibre GL JS does support globe mode. https://maplibre.org/maplibre-gl-js/docs/examples/display-a-... May we should update our examples to use globe mode when showing examples, especially those that show a world map. We will take that feedback into consideration!

You can use the Equal Earth projection with a plugin: https://equal.bbox.earth/maplibre-americas/

MapLibre's globe mode is both fantastic and performant. Also, it's literally just the one option to change it, and your tile formats/CRS don't need to change either.

It's the easiest way to escape from web mercator projections with no real downsides that I have discovered yet. Also, there is a built-in control if you want to offer a button to toggle between web mercator view, and globe view, since it's all just rendering changes.

obligatory West Wing: https://www.youtube.com/watch?v=vVX-PrBRtTY

This episode never made any sense at all. We already have globes for true sizes.

It's actually worse than that because the Web Mercator projection is unusable for navigation too - it doesn't preserve angles or area! (Angles are nearly preserved).

Well done Google. Slow handclap.

The NGA advised it's likely to cause geolocation errors of up to 40km near the poles:

https://www.gpsworld.com/nga-issues-advisory-notice-on-web-m...

You're a bit hasty, for the users that needs mercator projections, they should be able to get it, see: https://maplibre.org/maplibre-gl-js/docs/API/type-aliases/Pr...

Web mercator is fantastic map. It's well known of course, so very helpful to orient. Plus, its square and easily tile-able, which is good for performance. Shapes of countries are preserved. Plus, the lines are straight, which works great for on screen. Neat and tidy.

Who cares Greenland looks big when zoomed out. "Mercator distorts size" is one of those gis-nerd idee fixes, the first factoid they learn in class, and it overwhelms all thought.

> Who cares Greenland looks big when zoomed out.

You never know - one day, the geography of Greenland could matter quite a bit to the rest of the world.

Maybe you shouldn't have skipped that class if you don't think it's important.

I’m not sure it’s very useful to rehash an argument with very tenuous relation to the OP here. The normal reason to use the Mercator projection in these situations is (a) it’s what people are used to and (b) it preserves angles so if you zoom in on a street then up will still be north and roads that are at right angles in the real world appear to be at right angles on the map. The latter property is pretty desirable and hard to achieve without doing some weird transition between projections as you zoom. This matters more for Europe (and I suppose parts of British Colombia) where there is a high population density at latitudes that are pretty extreme in much of the world.

I think Apple Maps has a pretty reasonable compromise here of transitioning from a globe to Mercator as you zoom, but this is a less nice UI with a mouse as you need to click to rotate the globe instead of pointing and zooming only. I don’t think there’s anything in this data that would make that unachievable – you just need to reproject the vector data a bit as you zoom out – but it takes some tricky mathematics to get right and so hasn’t been done yet.

It's an important discussion because it's abundantly clear that almost nobody on this thread has a clue what they're talking about.

Web Mercator != Mercator.

I suggest most people on this thread need to go away ask the question "What's the difference between Web Mercator and Mercator".

For most uses of web maps (navigation on foot, by bicycle or by car) the angles seem to be close enough with Web Mercator, and the map is zoomed in to a small area so there's no concern about the area.

No-one is zooming out the "Find your nearest Tesco" map to see Greenland.

If two lines are at right angles in the ground and, say, outside the arctic/antarctic circles, what range of angles might be between them in a web Mercator projection?

Not everyone has a spherical monitor.

You can read more about why most web maps are like this and a quest to fix this in this article: https://www.mapbox.com/blog/adaptive-projections

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