Privacy: what sky stores and why

sky works without an account, without cookies and without ads. We collect as little as we can, and this page says what, where and why, in plain words.

Updated 18 October 2026

What stays in your browser

Most of what sky remembers is kept in your browser's own storage on this device, and is never sent to us unless you sign in and keep it with an account (below):

• your settings, theme, units and map layers;
• your last place on the map and your location, if you press My location (sky never asks for it by itself);
• your spotting log, saved studies and saved filter sets;
• the views you had open, the intro you have seen, the Scope's position settings.

To show traffic, your browser asks our server for the area you are looking at. That request carries the area, not who you are. Your browser also loads map tiles from OpenFreeMap and aircraft photos from planespotters.net directly, so those services see your address the way any website does.

Clearing your browser's data for sky.ampron.eu removes all of this.

Alerts and notifications

An alert rule (an aircraft, a place, military traffic, situations) is kept on our server so it can be checked while sky is closed. Without an account it belongs to a random code your browser made, not to you. A place rule holds that place. If you turn notifications on, we also keep the address your browser's push service gave it (Google, Apple or Mozilla run these services); an alert travels through it to your device. Delete all in My Sky removes the rules and the address.

If you make an account

An account is optional and free. It keeps your alerts, spotting log, saved studies, saved filter sets, settings and layers on all your devices. It stores:

• your e-mail address, when the account was made and when it was last used;
• the things above that you choose to keep with it;
• for each device you sign in on: a sign-in code (stored only in scrambled form), the kind of browser (for example "Safari on iPhone", nothing more) and when it was last used. A device stays signed in for 180 days of not being used;
• passkeys, if you add them: only the public half of the key, a name and dates. Your fingerprint or face never leaves your device;
• sign-in links we e-mail you, in scrambled form, for 15 minutes.

Your last place on the map and your location are not stored with the account; they stay on each device.

When signed in, sky sets one cookie, sky_s, that keeps you signed in on this device. It is needed for the account to work and is used for nothing else. Without an account, sky sets no cookie at all.

Sign-in e-mails are sent through our e-mail provider, Brevo, in France. We do not use your address for anything else unless you ask for product news below.

Aviation profile and product news: only if you choose

In your account you can say I work in aviation and add your organisation, title and sector. It helps us build sky for aviation professionals. It is optional and off until you switch it on.

Product news is a separate switch, off by default: occasional news from Ampron about sky and our aviation work. If you work in aviation and also switch news on, Ampron may write to you about it. Switch it off in your account at any time; each e-mail also says how.

Sky Dispatch e-mails: only if you choose

Signed in, My Sky → Sky Dispatch offers short digests (for example the Baltic GNSS day) every evening or every Sunday, by e-mail, as a notification, or both. Each topic is off until you switch it on. When you switch one on, change it or stop it, we keep a record of that choice so we can show you agreed: the time, how it was made (My Sky, an unsubscribe link, your mail program's unsubscribe button, or a bounced address), the sentence you agreed to, and a code made from your internet address with a secret key, never the address itself.

Every digest has a one-click unsubscribe that needs no sign-in, and a link to these preferences. Digests are sent through our e-mail provider, Brevo, in France. Your address is used for nothing else.

How we count visits, without cookies

We want to know how many people use sky and which parts help them, without following anyone. So:

• no cookies, no advertising or tracking services, and we never store your IP address or your browser's details;
• for each visit our server makes an anonymous code from a random value that changes every day, together with your address and browser. Only the code is kept. The day's random value is deleted at midnight (UTC), so tomorrow's code cannot be linked to today's, and no code can be traced back to you;
• your browser remembers the week of your first visit (a label shared by everyone who first came that week) and that it has been here before, so we can count new and returning visitors without knowing who anyone is;
• what is counted: which page and view, which features are used, the site you came from (its name only), campaign tags in the link, phone, tablet or desktop, whether sky is installed as an app, your language, your country (from our network provider Cloudflare), and whether the visit was signed in (not who).

Detailed records are kept 35 days, daily totals for longer. "Do not track" changes nothing here because nothing here tracks you: no record carries anything that identifies you.

Our server keeps no access log. Your address is held in memory for a few minutes to share the live data fairly and to stop abuse, then dropped.

Export and delete

Signed in, open My Sky → Account:

• Export my data downloads one file with everything your account holds;
• Delete account removes the account and everything kept with it at once and for good: e-mail, profile, synced data, digest subscriptions and the records of your choices about them, passkeys and every signed-in device. What is stored in your browser stays until you clear it;
• Signed-in devices lets you sign out any device.

You can also write to us and we will do it for you.

Where the data on the map comes from

Aircraft positions come from volunteers' receivers through adsb.lol (ODbL) and the OpenSky Network; airspace from openAIP; maps from OpenStreetMap contributors through OpenFreeMap; weather from NOAA, MET Norway, EUMETNET and national weather services; photos from planespotters.net, credited on each photo. This is public broadcast data about aircraft, not about you. Positions are estimates and not for navigation.

Who is responsible

Ask us anything about your data, or to see, correct, export or delete it. If you think we got something wrong, you can also complain to the Estonian Data Protection Inspectorate (Andmekaitse Inspektsioon).

Our servers run at DigitalOcean, with Cloudflare in front of them. If anything on this page changes, the date at the top changes with it.