External Map Layers: Adding WMS, WMTS and TMS Services to Your Map

The orthophoto you produced in the field is rarely enough on its own; most jobs need a zoning plan, a cadastral base or a satellite image from another date on top of it. Those bases usually already exist as map services published by municipalities, agencies and open-data programs — but downloading, converting and aligning them with your own data takes hours. External layers skip that step: you paste the service address, the layer appears directly on your map, and it can be shown, hidden and shared like any layer of your own.

Which services are supported?

Service type	What it gives you	Address form
WMTS / TMS / XYZ	A pre-rendered tile mosaic; the fastest and most reliable route	A https://…/{z}/{x}/{y}.png template ({-y} for TMS, {TileMatrix}/{TileRow}/{TileCol} for WMTS) or a plain service address
WMS	An image the server draws on demand for each view; needs a layer name	https://…/wms

A template address (one containing {z}/{x}/{y}) is the most robust option. If you paste a plain WMTS service address instead, the TileMatrixSet (opt.) and Image format (PNG/JPEG) fields appear; they must match what the server advertises. Only publicly reachable https:// addresses are accepted.

Adding a layer step by step

1. Click the External layers button in the bottom-right corner of the map; the Add WMTS / WMS button at the bottom of that panel opens the add dialog.
2. In the External layer (WMTS/TMS/WMS) dialog pick the service type at the top, give the layer a Name and paste the address into Service URL. The address is safety-checked as you type; any problem shows as a warning right under the field.
3. If you do not know the layer name, press Fetch layers from server: everything the server offers is listed under Found layers, and you simply pick one.
4. For WMS the Layer name is mandatory — leave it empty and you get "A layer name (LAYERS) is required for WMS." with the add button disabled. Choose the WMS version (1.3.0 or 1.1.1) and the coordinate system (CRS: EPSG:3857 or EPSG:4326); a Style (opt.) is optional. EPSG:4326 layers are placed approximately; pick EPSG:3857 if the server supports it.
5. If the service asks for a username/password or an access key, use Authentication (opt.). Credentials are stored encrypted, used only for tile requests and never shown on screen again.
6. Press Add layer. The layer appears on the map; extra parameters in the address (for example TIME=2023-06-01) are preserved.

No service at hand to try? The Fill with NASA GIBS example link fills the form with a working satellite imagery service — the quickest way to see the flow end to end.

Managing an added layer

Layers are listed both in the bottom-right External layers panel and on the Added tab of the add dialog. Each row has a Show / Hide toggle and an Opacity slider; a new layer starts at 85% opacity so the orthophoto underneath stays faintly visible. To remove a layer, use Delete on the Added tab.

Three common scenarios:

• Zoning / cadastral base: add the municipality's plan service and pull opacity down to 40–50%; boundaries read clearly on top of your orthophoto. In Turkey you can also fetch parcel boundaries without adding a service — see TKGM parcel query.
• Satellite comparison: add a satellite service from another date and toggle it against your own flight's orthophoto.
• Agency service: if your organisation's own feed requires an access key, that is what the authentication field is for.

External layers in shares

The share dialog has an External layers section next to your files; you tick the layers that go into the package. The recipient sees them read-only: from the bottom-right panel they can show/hide and change opacity on their own screen, but cannot add or delete layers. Tile traffic counts against the project owner's quota. For the sharing rules see PIN-protected sharing.

Limits and troubleshooting

Situation	What happens
Free plan	Adding is off — the add button is not shown; the Professional plan is required
Guest (share recipient)	Cannot add, view only
Daily traffic	1 GB of tile traffic per layer per day; beyond that you see "Daily quota exceeded for this layer." and the layer resumes the next day
Single tile size	At most 5 MB; larger tiles trigger "The server returned a response that is too large (limit exceeded)."
Response time	If the server does not answer within 8 seconds: "The server did not respond (timeout)."

Warning texts and fixes:

Warning	What to do
Invalid URL format. / Only https:// services are supported.	Copy the address exactly as published; http:// addresses are not accepted
Private/internal network IP addresses are not supported.	The service must be reachable from the internet; feeds visible only inside an office network cannot be added
Could not reach the server.	Open the address in a browser and confirm the service is up
No layers found on the server.	The service type may be wrong (WMTS instead of WMS or vice versa); switch it and fetch again
The server did not return the expected tile format.	Check the layer name for WMS, the matrix set and image format for WMTS
Server error (OGC): layer/tile-matrix-set/format may not match.	Layer name, TileMatrixSet and PNG/JPEG choice must match what the server advertises
Layer added but the map looks empty	Navigate to the area the layer covers; for WMS try EPSG:3857 if you chose EPSG:4326

Frequently asked

Question	Answer
Does it spend tokens?	No; viewing is token-free
Does it use my storage quota?	No — tiles are not stored, they come from the service every time
Can I add a password-protected service?	Yes; with username/password or an access key, stored encrypted
Can a recipient change the layer?	Only show/hide and opacity on their own screen; no adding or deleting
Which address is most reliable?	A {z}/{x}/{y} tile template
Available on the free plan?	No; the Professional plan is required