Privacy: your data lives on your phone

MeSienta is designed not to know who you are. That isn't a marketing line, it's an architectural decision: the app has no accounts, so there is nowhere for your data to pile up. This page sets out what is stored where, what travels over the network, and when.

What stays on your device (everything that matters)

• Your health profile and your family's: sensitivities, allergies, any conditions you record.
• Your symptom diary.
• Your favourites and your product history.

All of that is stored only in your browser's local storage, or in the installed app. It isn't uploaded to any server and nobody else sees it. There is a real trade-off, and we'll tell you just as plainly: if you clear your browser data or uninstall the app without exporting a copy, that data is gone, with no backup anywhere else. From the "Me" tab you can export a copy to a file that also stays with you.

The one exception, and you're the one who chooses it

The automatic encrypted backup is optional and comes switched off. If you turn it on, the app uploads to the MeSienta server a file that was encrypted on your device before it left: the server keeps it but cannot read it. Without the recovery code, which only you have, that file is noise.

How long it is kept: for as long as you use the app. If you stop using it and 18 months go by without a new copy being uploaded, the server deletes yours by itself, encrypted file and all. You don't have to do anything, and we have no way to warn you beforehand either: we don't know who you are. If you want it gone now, switch the backup off from the "Me" tab and it disappears there and then.

What travels over the network when you use the app

• When you scan or search: the barcode or the search text travels to Open Food Facts (an open food database). If the product isn't there, our server looks that same code up in USDA FoodData Central. Your identity and your profile never travel.
• When you analyse from a photo (AI): the picture of the label is sent to our server over an encrypted connection, and the server passes it to the AI provider solely to extract the text. It isn't stored: once the label has been read, the photo is discarded. What was read is kept when the product has a barcode: nutrients and ingredients are saved anonymously under that code, so that whoever scans it next has them without spending AI. That data comes from the label, not from you: it carries nothing that points back to you, and the app tells you so before you take the photo.
• When you ask for an explanation: the product analysis and your question travel. Your personal verdict, the one that names your conditions and your triggers, stays out of it unless you ask for it: either you tick the "include my personal verdict" chip in the chat, or you tap the question about your profile. Both leave the chip switched on and in plain view for as long as it is active.

Analytics: aggregate, cookie-free, on our own server

To find out how many people visit MeSienta we use Umami, hosted on our own server. It counts visits in aggregate, without cookies and without building user profiles: we know that "N people came in today", not who you are or what you scanned. Your scans, your profile and your diary go into no analytics at all.

No accounts, no advertising, no selling of data

There is no sign-up, there is no advertising, and no data is sold or passed on to third parties for commercial or advertising purposes. The only thing that leaves is what is described above, the bare minimum the analysis needs. The project is kept going by one person, not a data company.

Your rights, in practice

Because your health data stays on your device — and the optional backup only leaves it encrypted — exercising them is literally in your hands: export a copy ("Me" tab), delete everything (clear your browser data or uninstall the app), or take it to another phone (export and import). For any question about privacy, write to info@pin0.dev.

Last reviewed: 29 August 2026 · Written by Javier Pino