Your data in Alto

You can plan a route in Alto without an account. We keep as little as we can, we never sell it, and you can have all of it deleted by writing to us.

Last updated 5 November 2026

Who runs Alto

Alto is run by Arnau Ros, Carrer del Canonge Dorca, 17005 Girona, Spain. We decide how your data is used, which makes us its controller under the GDPR. For anything about your data, write to hello@macu.studio.

What we collect, and why

• Your account. If you sign in with Apple or Google, we receive your email address, your name if you share it, and which of the two you used. We use them to keep your account and to reply if you write to us.
• What you ask for. When you describe a route, we receive what you typed and the point the route starts from. We need both to build the route. We keep them in our server's logs, with the route we drew, so we can find and fix routes that came out wrong.
• Your location. If you allow it, your phone or browser tells Alto where you are, so routes can start there. It's sent to us only as the start of a route you ask for.
• Saved routes and your own runs. Routes you save, and GPX, TCX or FIT files you import, stay on your device. We don't receive them.
• Roads you share anonymously. If "Share them anonymously" is on, the app sends the roads you've used as short pieces of about 20 m. It leaves out the first and last 200 m and never sends times. They're stored under a random number that isn't linked to your account, and a road only shows on the map once 3 different people have used it. Turning the switch off deletes everything that was sent from your device.
• Links you share. When you share a route, we store that route under a random link so others can open it.
• Live location. If you share your live location, we keep only the last points, and delete them 12 hours after the last update.
• How the app is used. We log the screens and buttons used, your device type, language and screen size, so we can see what works. We don't use advertising or analytics companies for this.

Our server doesn't store your IP address. It uses it for a short time to stop abuse, and never writes it down.

We use this data to run the service you ask for (GDPR Article 6(1)(b)) and, for the logs and the anonymous roads, our legitimate interest in keeping Alto working and making routes better (Article 6(1)(f)). Location is used only after you allow it on your device.

Who else handles it

These companies handle data for us, only to provide the parts of Alto listed here:

• Hetzner (Germany): our server, where requests and logs are processed.
• Supabase (EU): sign-in and accounts, and our nightly backups, which are deleted after 14 days.
• Anthropic (USA): reads what you typed and the area you start from, to understand the route you want. It doesn't receive your name or email.
• Google (USA): place search, place photos and Street View. Our server sends it place names and map points, not who you are. Google also handles Google sign-in and the fonts on our website.
• Apple (USA): Sign in with Apple.
• Mapbox (USA) and other map providers (OpenStreetMap, OpenTopoMap, Esri, ICGC, IGN, Wikimedia): your device loads map images and photos from them directly, so they see your IP address and the map area you're viewing.
• Open-Meteo (Switzerland): weather for your route's start, rounded to about 100 m.
• Vercel and Cloudflare (USA): deliver the website and pass requests on to our server.

When a company is outside the EU, the transfer relies on the European Commission's Standard Contractual Clauses or the EU-US Data Privacy Framework.

AI

Alto uses Claude, an AI model made by Anthropic (USA), to understand what you type. When you send a message, your message and the area you start from go to Anthropic. Your name and email don't go with it.

Anthropic doesn't use your message to train its models. By sending a message in Alto, you agree to this.

Routes changed by dragging or with the buttons, without typing, send nothing to Anthropic.

Garmin and other connected services

If you connect a Garmin account, Alto sends the routes you choose to Garmin Connect so they appear on your watch or bike computer. If you also allow Alto to read your activities, we use them only to learn your usual pace and the roads you already know, for your own routes. Garmin data is stored on our server in Germany, is never sent to an AI service, is never shown to anyone else, and is deleted when you disconnect.

How long we keep it

• Your account: until you ask us to delete it.
• Logs: while we need them to run and fix Alto. They're deleted with your account when you ask.
• Anonymous roads: until you turn sharing off.
• Shared route links: until you ask us to remove them.
• Live location: 12 hours after the last update.
• Backups: 14 days.

Your rights

You can ask for a copy of your data, ask us to correct or delete it, object to how we use it, or ask us to stop using it. Write to hello@macu.studio from the email on your account and we'll do it within 30 days. If you think we got it wrong, you can complain to the Spanish data protection authority, the AEPD.

Children

Alto is not meant for anyone under 14, and we don't knowingly collect their data.

Changes

If we change how we use your data, we'll update this page and the date at the top. If the change is significant, we'll tell you in the app before it applies.