In short
- You can use the calculator without an account. Your work then stays in your browser.
- With an account, we store your email, your saved graphs and any audio you upload.
- No advertising, no analytics, no tracking cookies. We do not sell your data.
- Shared links and uploaded audio can be opened by anyone who has the link.
- You can delete your graphs at any time, and ask us to delete your account.
What we collect
If you create an account
- Email address, to identify your account and send sign-in codes.
- Password, stored only as a secure hash by our authentication provider. We never see it.
- Google profile details if you sign in with Google: your name, email address and profile picture.
What you save
- Saved graphs: the title and contents of each graph you save, with the time it was last changed.
- Audio clips you add while signed in, uploaded so your graphs can play them on any device.
What we do not collect
We do not run analytics, advertising or tracking scripts, and we do not build a profile of you. We do not access your microphone, contacts or location.
What stays on your device
Some information is kept only in your browser and is never sent to us:
| Item | Purpose |
|---|---|
| Your last graph | Offer to restore the piece you were working on. |
| Audio files you add | Play clips again after a refresh, without downloading them. |
| Theme, keypad and follow settings | Remember how you like the calculator set up. |
| Sign-in session | Keep you signed in between visits. |
These use your browser's local storage, not tracking cookies. Clearing your browser's site data removes them. Signing out removes the session.
Services we use
Mathestra relies on a few providers, who process data on our behalf to run the service:
- Supabase: accounts, sign-in, saved graphs and audio storage.
- Vercel: hosting. Like any web server, it records technical details of requests, such as IP address and browser, to deliver and protect the site.
- Google: sign-in with Google, if you choose it, and the web fonts the site loads, which means Google receives your IP address when the page loads.
- An email provider: to deliver sign-in and password reset codes.
These providers may store data on servers outside your country. They are bound by their own privacy and security commitments.
How we use data
- To provide the calculator, your account and your saved graphs.
- To send the emails you ask for: sign-in codes and password resets. We do not send marketing email.
- To keep the service secure and working, including preventing abuse.
We process account data to provide the service you signed up for, and technical data in our legitimate interest in running a secure website.
How long we keep it
- Saved graphs stay until you delete them, or until your account is deleted.
- Uploaded audio stays until your account is deleted. Deleting a graph does not delete the audio it used.
- Account details stay until you ask us to delete your account.
Your choices and rights
- Delete graphs at any time from My graphs.
- Use Mathestra without an account, keeping your work in your browser and in links.
- Ask us to access, correct, export or delete your data, including your whole account and uploaded audio, by writing to the address below. We reply within 30 days.
Depending on where you live, you may have further rights under data protection law, including the right to complain to your local data protection authority.
Children
Mathestra is not intended for children under 13, and we do not knowingly collect their data. If you believe a child has created an account, contact us and we will delete it.
Security
Connections to Mathestra are encrypted. Access to saved graphs is restricted so each account can reach only its own. No system is perfectly secure, so please use a strong password and keep it to yourself.
Changes to this policy
If we change this policy, we will update the date at the top. If a change is significant, we will say so on the site before it takes effect.
Contact
Questions or requests about your data: support@mathestra.space. See also our Terms of Service.