# Privacy: what stays on the device

RouteWasm calculates routes in the browser. This page lists what that does and does not keep away from servers, so you can describe it accurately in your own privacy notice.

## Never sent by local routing

- Start points, destinations and waypoints.
- Calculated routes, alternatives and their timing.
- Matrix origins, destinations and travel times.

The SDK has no routing server to send them to. Once the needed data is on the device, routing works without a network connection.

## Processed when data is downloaded

Map and routing data is delivered through Cloudflare from `tiles.routewasm.dev`. Like any web request, a download exposes:

- The device's IP address and normal HTTP metadata (user agent, time) to the delivery network.
- Which tiles are requested. Routing tiles cover roughly 20–30 km at the most detailed level, and map tiles follow what the user views. This reveals an approximate area of interest, not a route.
- Your project ID, carried in a short-lived token, to authorise delivery and count usage.

Our usage ledger stores, per request: project, month, bytes delivered and a request ID. It does not export IP addresses, cookies, authorisation headers, query strings, tile paths or route inputs.

## Separate from routing

- Your RouteWasm account (email, password hash, project settings) lives on our account service.
- Your own app's backend, analytics, crash reporting and hosting are outside RouteWasm. They can still collect location data; review them separately.
- Planned services, such as hybrid server routing and address search, would receive the queries sent to them. They are not live and would be opt-in.

## GDPR

Calculating on the device supports data minimisation (Article 5(1)(c)) and data protection by design (Article 25): there is no trip data for us to store, leak or disclose. It does not make your app compliant by itself. You remain responsible for your app's lawful basis, notices and other processing. Tile downloads involve IP addresses, which are personal data under the GDPR.

## Fewer servers involved

- Self-host the routing data and map tiles: the SDK is free and works with compatible self-hosted data, so no RouteWasm server is involved.
- Download areas ahead of time, for example on Wi-Fi, so routing later needs no requests.