Privacy Policy

Effective date: 5 October 2026 · Last updated: 5 October 2026

This policy explains what personal data Synt processes, why, for how long, who helps us and what rights you have. Synt is the study app for iOS and Android that turns your notes, PDFs, photos, web pages and videos into summaries, quizzes, flashcards and study plans, together with its websites (synt.app and the web version of Synt at app.synt.app). We have tried to keep it short and clear.

1. Who is responsible

The data controller is Roberto Díaz Badra – Disruptive Normality, a self-employed developer based in Spain.

Contact for any privacy question: info@synt.app

2. The essentials

• In the app you can start without a name or email: Synt creates an anonymous app ID. If you sign in (email, Google or Apple), your study material is also saved to your account so you can use it on other devices and on the web.
• On the web (app.synt.app) you need an account.
• The material you send us (text, PDFs, photos, links, videos) is processed by our servers and our AI providers only to create what you ask for.
• We do not use your material to train AI models and we do not sell your data.
• Payments are handled by Apple or Google in the app and by Stripe on the web. We never see your card details.
• On the websites, Google Analytics and Google Ads only use cookies if you accept them in the cookie notice (EU/EEA, UK and Switzerland).
• When you create an account on the website, we store the advertising campaign that brought you there (UTM source, medium, campaign and content), without ad or click identifiers. You can object at any time (section 5).

3. What data we process

Material you send us and what we create from it

• The text you type or paste, the PDFs and documents you upload, the photos you take or choose (only after you allow access), and the links to web pages or videos you submit.
• What we create for you: summaries, quizzes, flashcards, concept maps, mock exams, study plans and their results (for example, your quiz answers and progress).
• The exams you add (subject, date) and your study preferences, so we can build your plan and remind you.

This material may contain personal data about you or other people. You decide what you send.

App and device data

• An anonymous user ID created by the app (Firebase Authentication).
• Device and app information: device model, operating system, app version, language, country or region, currency and time zone.
• Usage events: for example, when you open the app, create a material, view a subscription screen or use a feature, and your answers to the welcome questions.
• Crash reports and diagnostic logs.
• A push notification token, if you allow notifications. For exam reminders, the app sends our server a short summary of your upcoming exams (subject and date).
• Advertising identifiers (in the app only; see section 5).

Your account

If you sign in in the app or use app.synt.app: your email, your account ID, how you sign in (email and password, Google or Apple) and the dates you joined and last signed in. If you sign in with Google or Apple, they give us your email and, if shared, your name. Your password is handled by Firebase Authentication and we never see it.

Purchases

• In the app: your subscription status, the product, trial and renewal dates, and an anonymous purchase ID. Apple or Google process the payment; we do not receive your card details.
• On the web: Stripe processes the payment. We receive from Stripe the plan, amount, payment and renewal dates, subscription status, country (for VAT) and invoices, but never your full card number. Stripe processes your payment data on our behalf to charge you and, for its own purposes such as fraud prevention and legal compliance, as an independent controller.
• If you join through an invitation link or a creator's offer: who invited you or which offer you used, so we can apply the reward or discount.

Feedback and support

Bug reports, survey answers, feature votes, cancellation reasons, and the messages and emails you send us (with your email address so we can reply).

Websites

• Visits to synt.app and app.synt.app: see section 11.
• The free preview on some synt.app pages: the text you paste is sent to our server and our AI provider to create the preview. To apply the daily limit we use your IP address; our logs keep only an irreversible fingerprint of it.
• Campaign of origin: see section 5.

4. What we use data for and on what legal basis

• To provide Synt (process your material and create summaries, quizzes and plans, keep your account and sync your material, process payments and keep your subscription in sync, send the reminders you ask for): performance of our contract with you (Article 6(1)(b) GDPR).
• Push notifications: your consent, given through your device's permission. You can turn them off at any time in your device settings.
• Keeping Synt working and secure (crash reports, diagnostics, abuse prevention, usage limits): our legitimate interest in offering a reliable and secure service (Article 6(1)(f) GDPR).
• Understanding and improving the app (product analytics, subscription screen tests, your feedback): our legitimate interest in improving Synt. We use pseudonymous IDs, not your name or email. You can object at any time by writing to us.
• Analytics and advertising cookies on the websites: your consent (section 11).
• Campaign of origin of web accounts: our legitimate interest in measuring the effectiveness of our advertising (section 5).
• Legal obligations (for example, tax and accounting rules such as issuing and keeping invoices, or answering requests from authorities): legal obligation (Article 6(1)(c) GDPR).

We do not sell your data and we do not make decisions based solely on automated processing that produce legal or similarly significant effects on you.

5. Advertising and campaign measurement

• Websites (synt.app and app.synt.app). We use Google Ads and Google Analytics to measure how our campaigns perform. In the EU/EEA, the UK and Switzerland, these tools only use cookies or device identifiers if you accept them in the cookie notice, and you can change your choice at any time. If you accept, Google may also use this information to show you Synt ads on other sites.
• Campaign your account came from. When you create an account on the Synt website, we store with it the advertising campaign that brought you there: the source, medium, campaign and content shown in the link (UTM parameters). We do not store ad or click identifiers or your IP address, and we use no cookies for this: the data travels in the link itself. We do this based on our legitimate interest in measuring the effectiveness of our advertising. You can object by writing to info@synt.app, and we will delete this data. We keep it for as long as your account exists.
• App. The free version of the app may show ads through Google AdMob, and the app uses the Meta (Facebook) SDK to measure app installs and events from our campaigns. On iOS, advertising identifiers are only used for tracking if you allow it in Apple's prompt («Allow apps to request to track»). On Android, you can reset or delete your advertising ID in your device settings.

6. Who helps us (service providers)

We share data only with the providers we need to run Synt. They process it on our behalf and may only use it to provide their service to us.

• Google Firebase and Google Cloud (Google): sign-in, database, file storage, server functions that process your material, push notifications, remote configuration, Firebase Analytics and Crashlytics, and Gemini AI models. Servers mainly in the United States.
• OpenAI: creates summaries, quizzes, flashcards, plans and other results from your material. United States.
• Content import providers (such as Firecrawl and AssemblyAI): fetch the text of the web pages and videos whose links you submit. United States.
• RevenueCat: manages subscription status for the app and the web. United States.
• Stripe (Stripe Payments Europe, Ireland, and Stripe, Inc., United States): web payments, renewals, invoices and the portal where you manage your subscription.
• Superwall: shows subscription screens in the app and measures how they perform. United States.
• Amplitude: product analytics and feature tests. United States.
• Google Analytics and Google Ads (websites, with your consent) and Google AdMob (app ads).
• Meta Platforms: measurement of app installs and events from our campaigns.
• Apple and Google: App Store and Google Play distribution and payments, and sign in with Apple or Google. They act as independent controllers; see their privacy policies.
• Our email provider, to answer the messages you send us.

If you share a quiz with a link, anyone with the link can see it. We may also disclose data when the law requires it, or to protect our rights or the safety of users.

7. AI processing

To create what you ask for, we send your material from our servers to our AI providers (OpenAI, Google Gemini), which return the result to us. They process the content to return the result and may keep it for a short period under their own policies (for example, to prevent abuse). We do not use your material to train AI models. AI-generated summaries and questions can contain mistakes: check them before relying on them for an exam.

8. How long we keep data

• Your material and what we create from it: while you keep it in Synt. When you delete it in the app or on the web, it is deleted from our database; you can ask us by email to delete your account and any remaining copies (for example, uploaded files).
• Anonymous ID and basic app data: while you use Synt. You can ask us by email to delete them at any time (section 10).
• Account data and the campaign of origin: for as long as you have the account, until you delete it or ask us to delete it.
• Subscription data and invoices: while your subscription is active and afterwards for as long as needed for accounting, tax and legal claims (generally up to 6 years under Spanish law).
• Analytics and crash data: for the retention period set in each tool (Google Analytics: 14 months), after which it is deleted or anonymised.
• Feedback and emails: for as long as needed to answer you and improve Synt.

9. International transfers

Several providers are based in the United States, so your data may be transferred outside the European Economic Area. When this happens, transfers are made with appropriate safeguards, such as the European Commission's Standard Contractual Clauses or the EU–U.S. Data Privacy Framework. You can ask us for more information about these safeguards.

10. Your rights

You can ask us to access, correct or delete your data, to restrict or object to its processing, and to receive it in a portable format. Where we rely on your consent, you can withdraw it at any time without affecting earlier processing.

To exercise your rights, email info@synt.app. If you use the app without an account, we may ask for details that help us find your data (for example, your App Store or Google Play purchase receipt). We will reply within one month.

If you are not satisfied with our answer, you can file a complaint with the Spanish Data Protection Agency (Agencia Española de Protección de Datos, www.aepd.es) or with the data protection authority of your country.

11. Websites and cookies

You do not need to give us personal data to visit synt.app; to use app.synt.app you need an account. On both sites we use:

• Google Analytics 4 and Google Ads, only if you accept cookies in the notice (in the EU/EEA, the UK and Switzerland they stay off until you accept; until then Google receives only cookieless signals without identifiers). Their cookies (such as _ga and _gcl_*) last up to 2 years.
• Amplitude on app.synt.app, for product analytics, only if you accept cookies in the notice.
• Local storage in your browser to remember your cookie choice and your language and, on app.synt.app, to keep you signed in (Firebase Authentication). This is strictly necessary and does not track you.
• Stripe: when you pay or manage your subscription you do it on Stripe pages, which use their own cookies needed to process the payment and prevent fraud.

You can change your choice at any time by deleting this site's data in your browser; the notice will appear again.

12. Children

Synt is not intended for users under the age of 18. We do not knowingly collect personal data from people under 18. If you believe a minor has shared personal data with us, contact us and we will delete it.

13. Security

We use encrypted connections, access controls so that only you can read your account's material, and signed requests between the app and our servers. No system is completely secure, but we work to protect your data and will notify you and the authorities of a breach when the law requires it.

14. Changes to this policy

We may update this policy when Synt or the law changes. We will publish the new version here with its date and, if the changes are significant, we will also let you know in the app or on the website.

15. Contact

Roberto Díaz Badra – Disruptive Normality
Email: info@synt.app