SaunaHash app — privacy
The app is the Helsinki-region sauna atlas on your phone. This page says exactly what it does with data, and it is short because the app does very little.
SaunaHash app · Privacy · Support · The atlas · Updated 2026-10-01
What the app stores on your phone
- The atlas
- A copy of the dataset saunahash.com publishes at /atlas/helsinki.json (104 records, as of 2026-10-01) is bundled into the app, so it works with no connection. When you are online the app refreshes it and keeps the last copy in the app's own storage.
- Favourites
- The records you star are kept as a list of record ids in the app's own storage. They are not sent anywhere and there is no account to sync them to.
The one network request
The app makes one kind of request: an HTTPS GET to saunahash.com/atlas/helsinki.json to refresh the atlas, on launch and on pull-to-refresh. It carries no identifier, token, location or user data — only the standard request headers and, when the app has one, the file's ETag so an unchanged file is not downloaded again. saunahash.com is hosted on Vercel, whose servers see the request's IP address in ordinary server logs; SaunaHash reads no per-request data from them. No other host is ever contacted by the app.
Location
The Nearby tab can sort the atlas by distance from where you are. It asks Android for foreground location permission only when you tap Use my location, never at launch and never in the background. The position is read once, kept in that screen's memory while it is open, used on the phone to sort the list, and then dropped. It is never written to storage, never attached to the atlas request and never sent to SaunaHash or anyone else. If you decline, the tab says so and offers the municipality filter instead. You can withdraw the permission at any time in Android Settings › Apps › SaunaHash › Permissions.
What the app does not do
- No account, sign-in or registration.
- No analytics or crash-reporting SDK, no advertising, no advertising identifier.
- No notifications, no background work.
- No payments or in-app purchases.
- No WebView: links open in your browser. Links to SaunaHash's own sites carry plain UTM tags (so saunahash.com can tell app visits from web visits); links to operators and open-data sources are opened untouched.
Deleting your data
Everything the app holds is on your phone. Uninstalling the app, or clearing its storage in Android Settings, erases the atlas copy and your favourites. There is nothing to delete on our side.
The data in the atlas
The atlas describes sauna venues, not people. Open data: Pääkaupunkiseudun palvelukartta, City of Helsinki, CC BY 4.0, retrieved 2026-10-01 · Lipas.fi, Jyväskylän yliopisto (University of Jyväskylä), CC BY 4.0, retrieved 2026-10-01. Operator and municipal pages contributed facts only. Dataset licence: CC BY 4.0, attribution “SaunaHash atlas, saunahash.com”. Corrections: support.
Who publishes the app
Published by SaunaHash (saunahash.com), Helsinki, Finland. Questions about this page: hello@jukkablomberg.com.
Updated 2026-10-01. Google Play listing: SaunaHash: Helsinki Saunas (package com.saunahash.app). Availability: Finland.