OpenTopography API Key Guide for BlenderGIS: Free DEM & Elevation Data

OpenTopography’s global elevation datasets — SRTM and more — are what give BlenderGIS its real 3D terrain. Since 2022 the service requires a free API key. Here’s how to register, request your key, plug it into BlenderGIS, and start downloading DEM data.

What OpenTopography gives you (and why it needs a key)

OpenTopography is a research-data facility that serves high-resolution topography — digital elevation models (DEMs) covering most of the planet, including the widely used SRTM datasets. BlenderGIS uses it as the source when you download elevation to build real 3D terrain meshes in Blender.

The service itself is still free. But since 2022, OpenTopography has required every user to authenticate with a personal API key — a measure to prevent abuse and keep the free service sustainable for the research community. Without the key, elevation requests are rejected, typically with an HTTP 403 or a silent empty result.

Note the division of labor in BlenderGIS: the OpenTopography key is for elevation/DEM downloads. Satellite imagery, street basemaps, and place search run through MapTiler and need a separate key — see our MapTiler key guide, or the general API key setup overview for the full picture.

Step 1: Register and request your free key

1. Go to opentopography.org and create a free user account.
2. Log in and navigate to the API key / account section to request an API key. Approval is typically quick.
3. Copy the issued key — a long alphanumeric string — and keep it somewhere safe.

There is no charge at any point: registration is free and the key grants access to the free data services. OpenTopography may ask what you’ll use the data for — a one-line answer like “terrain visualization in Blender via the BlenderGIS addon” is perfectly fine.

Step 2: Enter the key and download elevation

1. In Blender, open Edit > Preferences > Add-ons and expand BlenderGIS.
2. Find the Elevation section. On v2.2.10 and newer it shows a dedicated API key setting dialog — paste your OpenTopography key there.
3. Save your preferences.
4. Use the addon’s elevation import (GIS > Web geodata > Elevation) to download DEM data — SRTM and other datasets — for your area of interest.

A couple of practical notes. First, make sure you’re on a compatible build: the latest stable is v2.2.15 (released Dec 20, 2025), downloadable from our download page. Minimum Blender is 2.83 LTS; Apple Silicon Macs should use at least v2.2.10 (which is also the version that introduced the API key dialog). Blender 4.2+ users need v2.2.12 or newer for the MapTiler side of things.

Second, elevation downloads cover large areas at modest resolution — zoom into a reasonably tight region for the best detail-to-download-time ratio. If a download fails, check the key first (typos and stray spaces are classic), then consult our troubleshooting guide.

Symptoms of a missing or bad OpenTopography key

• Elevation download fails with HTTP 403.
  The textbook missing-key error — the server refuses to serve DEM data to an unauthenticated request.
• The operator finishes but produces no terrain.
  Sometimes the failure is silent: no error, no mesh. Always suspect the key before reinstalling anything.
• It worked in 2021 and broke later.
  That’s the 2022 key mandate catching up with you. Old tutorials predate the requirement — register for a key and the same workflow works again.

Frequently asked questions