Today we are releasing Tile Kiln, a small, simple service for converting GeoTIFF rasters into tilesets that can be used directly in MapLibre maps.
If you have a georeferenced raster, such as a drone orthomosaic, survey image, scanned map, or other TIFF/BigTIFF GeoTIFF file, Tile Kiln gives you a short path from source file to web map. Drop in the file, choose a few tile options, upload it, wait for processing, and then use the generated TileJSON URL in your MapLibre application.
Under the hood, Tile Kiln creates an upload job, gives the browser a presigned upload URL, converts the raster into a PMTiles archive, and serves it as raster tiles through our tile infrastructure. The uploader also performs client-side checks before upload: file extension, TIFF/BigTIFF header, dimensions, bit depth, GeoKeys, and bounds where available. When conversion finishes, the demo page shows a MapLibre preview and copyable source/layer code.
Why We Built It
We are currently working on a map product that has not been released yet. A core requirement for that product is letting users upload their own drone maps and other georeferenced rasters, then display those rasters inside an interactive web map.
Tile Kiln is part of that infrastructure. Once it was useful enough for our own work, it made sense to make a public version available too. There are many cases where someone just needs to get a GeoTIFF into a MapLibre map without first setting up a tiling pipeline, object storage, signed uploads, PMTiles output, and TileJSON hosting.
How To Use It
The quickest path is the Tile Kiln uploader. The public uploader accepts GeoTIFF-compatible TIFF or BigTIFF files up to 100 MB. You can choose PNG, JPEG, or WebP output, select the tile size, set the resampling method, and optionally provide minimum and maximum zoom levels.
When processing completes, Tile Kiln gives you a TileJSON URL that can be used as a raster source in MapLibre:
map.addSource("uploaded-raster", {
type: "raster",
url: "https://tiles.kmproj.com/uploads/raster/.../source.json",
tileSize: 512,
});If you want to automate the same workflow, there is also API documentation. The API flow is: create a job, upload the GeoTIFF to the returned presigned URL, poll until conversion finishes, and then use the generated TileJSON URL.
Free Service Limits
Tile Kiln is available as a free public service, but it has limits.
For free uploads, you must provide an email address. This is for operational contact: if a tileset starts disrupting service for others, we need a way to reach the person responsible for that upload. Public job responses do not expose the email address.
Free uploads also expire automatically:
- If you provide a secret change key, the tileset expires after six months. Keep the change key somewhere safe, because it is also what lets you manually delete the tileset before it expires.
- If you do not provide a change key, the tileset expires after one month. In that mode, you cannot manually delete it after uploading.
The free service is meant for experiments, prototypes, and lightweight public use. It is not a permanent hosting guarantee.
Paid and Non-Expiring Use
For paid service, API key access, or indefinite expiry, contact us directly. We can discuss pricing and terms based on expected usage, traffic, file sizes, retention needs, and operational requirements.
Tile Kiln is small by design. It does one job: take a GeoTIFF raster and turn it into something you can put on a MapLibre map. If that is useful for your project, try the uploader or read the API documentation.