Open Source | Allmaps

Allmaps is open source, with libraries, plugins and APIs you can use in your own work.

Put historical maps on your website

Add georeferenced maps to MapLibre, OpenLayers or Leaflet. Each plugin loads Georeference Annotations and warps the original IIIF images in the browser.

Try it below: pan, zoom and change the opacity to compare the historical map with today’s streets.

Built with the Allmaps MapLibre plugin. Richards standard atlas of Holyoke, 1911: Norman B. Leventhal Map & Education Center at the Boston Public Library, via Digital Commonwealth.

// Imports and worker setup · 7 lines

import { Map, setWorkerUrl } from 'maplibre-gl'
import { WarpedMapLayer } from '@allmaps/maplibre'
import 'maplibre-gl/dist/maplibre-gl.css'
import workerUrl from 'maplibre-gl/dist/maplibre-gl-worker.mjs?worker&url'

setWorkerUrl(workerUrl)

const map = new Map({
  container: 'map',
  style: 'https://basemaps.cartocdn.com/gl/voyager-gl-style/style.json',
  maxPitch: 0
})

const warpedMapLayer = new WarpedMapLayer()

const annotationUrl = 'https://annotations.allmaps.org/manifests/071c6ba31f9c88d4'

map.on('load', async () => {
  map.addLayer(warpedMapLayer)
  await warpedMapLayer.addGeoreferenceAnnotationByUrl(annotationUrl)

  const bounds = warpedMapLayer.getBounds()
  if (bounds) map.fitBounds(bounds, { padding: 30 })
})

The 1911 atlas of Holyoke over a modern map, centered on the Dwight Street canal bridges

Map opacity

Explore the plugins and code examples

Build with the individual parts

Use Allmaps’ TypeScript libraries in your own projects. Work with annotations, transform coordinates or render maps.

@allmaps/annotation
Read and create Georeference Annotations.
@allmaps/transform
Transform image pixels into geographic coordinates and back.
@allmaps/project
Transform coordinates using map projections.
@allmaps/render
Render georeferenced maps in the browser or on a server.

Browse all libraries

import { GcpTransformer } from '@allmaps/transform'

const gcps = [
  { resource: [0, 0], geo: [4.9, 52.38] },
  { resource: [1000, 0], geo: [4.92, 52.38] },
  { resource: [0, 1000], geo: [4.9, 52.36] }
]
const transformer = new GcpTransformer(gcps)

// Image pixels
const point = [500, 500]
console.log(transformer.transformToGeo(point))
// Longitude, latitude
// ≈ [4.91, 52.37]

These example control points connect image pixels (x, y) to longitude and latitude. Use your map’s control points to transform your own coordinates. Learn how to transform coordinates →

Connect your tools and workflows

Allmaps APIs

Retrieve Georeference Annotations, query maps and connect Allmaps to your collection systems. The API documentation explains the available endpoints and authentication.

Explore the APIs

Allmaps CLI

Work with maps from your terminal. Parse annotations, transform coordinates and process IIIF resources in scripts and repeatable workflows.

Get started with Allmaps CLI

Need data for your project? Download the open georeference dataset to explore and reuse maps across collections.

Explore the source code

The whole Allmaps project is open source. You can read the code, adapt it to your needs and contribute improvements.

Licenses

The core libraries and mapping plugins use the MIT license. Applications and services have their own licenses, listed in each component’s repository. Public georeference data is released under CC0.

Use of the hosted Allmaps services is covered by the Terms & Usage.

Help improve Allmaps

Report a bug, suggest an improvement, contribute code or help with the documentation. You can join the discussion on GitHub or get in touch.

Explore the code on GitHub

The Allmaps open source organization on GitHub