How to use the Macrostrat API in JavaScript

Geologic maps, rock columns and stratigraphy data. This guide calls it from JavaScript with code we've run against the live endpoint.

Online · 694 msEndpoint tested Oct 24, 2026

1. What you need

Any modern browser. Paste the code into the DevTools console or a module script tag.

No API key or sign-up. Endpoint: https://macrostrat.org/api

2. Make the request

JavaScript

const res = await fetch("https://macrostrat.org/api");
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const data = await res.json();
console.log(data);

3. The response

Trimmed from the live response on Oct 24, 2026.

JSON

{
  "success": {
    "v": 2,
    "description": "This is the root of the Macrostrat API",
    "changelog": "/changes",
    "license": "CC-BY 4.0. More info at /meta",
    "routes": {
      "/columns": "Search and summarize columns based on unit properties or geographic location",
      "/sections": "Summarize units by gap-bound packages",
      "/units": "all Macrostrat units matching search criteria",
      "/fossils": "Paleobiology Database (http://paleobiodb.org) collections matched to Macrostr...",
      "/stats": "statistics about the Macrostrat database",
      "/paleogeography": "Returns paleogeography geometry from \"Wright et al. (2013) Towards community-...",
      "/geologic_units/map": "Geologic map units from various data sources",
      "/geologic_units/map/points": "Query point features from geologic maps",
      "/geologic_units/map/legend": "Retrieve legends for geologic map units",
      "/measurements": "measurements",
      "/age_model": "Get all components of column age models; mostly unit_boundaries but can inclu...",
      "/eodp": "eODP Macrostrat Baggage Stripper Import"
    }
  }
}

4. Before you ship

Set a timeout and handle non-200 responses: free APIs can rate-limit or go down.
Cache responses where you can, instead of calling the API on every page view.
Browser calls depend on CORS. If a request is blocked, move it to a server or serverless function.
Read the official documentation ↗ for rate limits and terms of use.

FAQ

Does the Macrostrat API need an API key in JavaScript?

No. The Macrostrat API works without an API key, so the JavaScript example runs as-is.

Can I call the Macrostrat API from the browser?

Yes. It sends CORS headers, so front-end JavaScript can call it directly.

What does the Macrostrat API return?

JSON. The example response on this page is trimmed from a real response our health check received on Oct 24, 2026.

Same API in: Python · Node.js · PHP · Java · Go · Ruby · C#
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