Last updated September 2026
Stellato Labs is a racket fitting and string-tracking tool. This page explains what it collects and what it does with it. There is no ad tracking, no advertising profile, and no selling of data — this is the whole policy.
By default, nothing you enter leaves your device. Your bag, your fitting answers, and your settings are stored in your browser's local storage only. We never see this data, and closing your browser doesn't lose it, but a different browser or device won't have it either.
Creating an account lets your bag follow you to another device. If you do, we store on our server:
That's it — no payment details are ever collected (we don't sell anything through the app), and no data beyond what's listed above.
If you choose "Continue with Google," we ask Google only for your name, email address, and whether Google considers that email verified. We use this to create or match your account by email — we do not request access to your Gmail, Google Drive, contacts, or any other Google data, and we never post anything on your behalf.
An account uses one cookie to keep you signed in. It is not used for tracking or advertising, and it is cleared when you sign out. It is the only cookie this site sets.
We use Vercel Web Analytics to count visits and to see how many people who start a fitting reach the end of it. It is cookieless: it sets nothing on your device, assigns you no identifier, and cannot follow you to any other site. What it records is the page, and whether a fitting was started or finished — never your answers, your rackets, your name, or your email.
These counts are aggregate and are not linked to your account. We use them to work out which parts of the app are confusing, and nothing else.
Reminder emails are not switched on at the moment, and the app does not offer to send them. If that changes, it will be opt-in: off by default, at most one email per racket, and every email carrying a one-click unsubscribe link that turns it off immediately.
We also send one transactional email that is not optional in the same sense: if you ask to reset your password, we email you a link to do it. That is only ever sent because you asked for it, and the link stops working after an hour.
Settings → Danger zone lets you delete your account and everything attached to it, or clear the data on just this device, at any time.
Questions about this policy: stellatostrings@gmail.com