Legal
Privacy Policy
Last updated 27 July 2026
Marble is an iPhone app that estimates the nutrition in your meals from a photo and coaches you toward a goal. This page explains what it keeps, what leaves your phone, and how to get rid of all of it.
The short version. There is no account and no sign-up. Your meals, photos, goals and conversations are stored on your iPhone, not on a server. Photos and messages are sent to Anthropic to be analysed and the answer comes straight back — they aren't kept. Nothing is sold, and there is no advertising or tracking of any kind.
What stays on your phone
Marble stores your information in the app's own storage on your device. That includes:
- Your goals — sex, height, weight, activity level, the goal you picked, and the calorie and macronutrient targets calculated from them.
- Your meals — the photos you take, the dish, and its calories, protein, carbohydrate and fat.
- Your weigh-ins — the number and the date, in a file on your device. These never leave your phone at all: the trend, the verdict and every correction to your calorie target are computed here and sent nowhere.
- Your conversations with the coach.
- Your settings — theme, and your weigh-in reminder time if you set one.
None of this is uploaded to an account, because there isn't one. You never give Marble an email address, and there is nothing to log in to.
What leaves your phone
Meal photos and coach messages
To read a meal or answer a question, Marble sends that photo or message to Anthropic's Claude API and shows you what comes back. The request is processed to produce your answer and is not stored in a Marble database afterwards. Marble does not use anything you send to train any model.
A random app identifier
Each install generates a random identifier that is sent with those requests so that AI usage can be rate-limited. The only thing recorded against it is a daily count of requests. It is not linked to your name, your email, your device's advertising identifier, or anything you log — and it is gone when you delete the app.
These requests are served through Supabase, hosted in the United States, which passes them to Anthropic. Marble does not collect your contacts, your location, or your health records, and it does not read from Apple Health.
There are no advertising networks, no data brokers, and no third-party analytics or trackers in Marble. Your information is never sold.
How long it's kept
Your meals and photos stay on your phone until you delete them. Deleting a meal removes that entry and its photo immediately. Because there is no server-side copy, there is no archive to clear out.
Deleting your data
Delete individual meals inside the app, or delete the app to remove everything at once — your goals, meals, photos and conversations all live in the app's own storage and go with it. There is no account to close and nothing left behind on a server.
Children
Marble is not intended for children under 13.
Not medical advice
Marble estimates nutrition and suggests targets. It is not a medical device and does not provide medical advice, diagnosis or treatment. Talk to a doctor or a registered dietitian before making significant changes to how you eat, particularly if you have a health condition or a history of disordered eating.
Changes
If this policy changes in a way that affects what is collected or who it is shared with, the date at the top will change and the app will say so.
Contact
Questions about any of this, or requests about your data: support@getmarble.app