Privacy Policy

Last Updated: October 29, 2026

This policy describes how eBook Translator (the "App") handles your data: what remains on your device, what we process and keep, what service providers process for us, and what choices are available to you.

1. Data Stored Only on Your Device

Your books, reading progress, bookmarks, highlights, glossary, and any personal API keys you enter are stored locally on your device. We cannot access this data, and it remains on your device until you delete it or uninstall the App. Because we hold no copy, we cannot restore this data once the App is uninstalled. The only book content that leaves your device is what is needed to perform a translation you request, as described in Section 2.

2. Translation Text

When you request a translation, paragraphs of the chapter being translated are sent for translation, and the translation is returned to your device. The request also includes the book's title and genre, and any of your glossary terms that appear in that text — context that produces a better translation. We use this text only to translate it and to monitor and fix translation quality; we do not read your books for any other purpose, and we do not use the text to identify you.

Depending on the App version and settings, a translation takes one of two routes:

• Direct translation. The App sends the text to Google Gemini through Google Firebase. For quality monitoring, the text sent and the translation returned are recorded in our Google Cloud logs, together with technical request details, and are deleted after 30 days. We do not add your name, email address, or an account to these records.
• Server translation. The App sends the text to our translation server (Google Cloud, Belgium region), which has it translated by Google's Vertex AI and keeps:
  • the translation, until your device confirms it was received and for no longer than 7 days, so that an interrupted translation can be delivered to your device again;
  • only when a translation does not complete normally (for example, paragraphs are missing or the output is cut off): the full request, including the original text, and the raw output, for 30 days, so that we can find and fix the cause.
  Translations and requests kept on our server are linked to your anonymous account (Section 3), not to your name or email address.

The text comes from your books and may contain personal information about people mentioned in them; we process it only for the purposes described here.

Translating the text is necessary to provide the translation you request; where data protection law applies, that necessity is the legal basis. Keeping text to monitor and fix translation quality is based on our legitimate interest in a working service; you can object to it (Section 7). If you configure your own API key (Section 5), the text goes directly to that provider and none of the above applies.

3. Data We Collect

• Usage statistics: screens viewed, features used, device model, and operating system version. We use this data to improve the App. Where the law requires it, it is processed only with your consent.
• Crash reports: technical details of errors that occur in the App. We use them to identify and fix defects. Where the law requires it, they are processed only with your consent.
• Advertising ID: your device's advertising identifier, used by Google AdMob to serve ads and measure their performance. Advertising funds the App. Where the law requires it, this is processed only with your consent.
• Translation text: as described in Section 2.
• Anonymous account (server translation only): the first time you use server translation, the App signs in to Google Firebase Authentication anonymously. This creates a random user identifier and, on our server, an account record with a random account number, its creation time, and the date you last used server translation (updated at most once a day). It is not linked to your name, email address, or advertising ID. We use it to deliver your translations, to apply usage limits, and to prevent abuse.
• Translation usage records (server translation only): for each translation, a record without any text: the language pair, the number of paragraphs and glossary terms, the processing time and cost, the AI model, and the App version. We use them to run the service, control costs, and detect abuse.
• Rewarded ad verification (server translation only): when you watch a rewarded ad to unlock a translation, Google AdMob confirms to our server that the ad was completed. The confirmation carries a one-time ticket number created for that translation, not your advertising ID.
• Network data: as with any internet service, our server and Google record your IP address in technical request logs. We use these logs only to operate and secure the service; our Google Cloud logs are deleted after 30 days, and Firebase Authentication keeps sign-in IP addresses for a few weeks.

None of this data includes your name or your email address. Processing for the anonymous account, usage records, ad verification, and network data is based on our legitimate interest in operating a secure and affordable service.

4. Your Controls

Settings → Legal & Privacy contains separate switches for usage statistics and crash reports.

• In the EEA, the UK, and other regions where the law requires prior consent, both are off by default and nothing is collected until you enable them.
• In other regions, both are on by default and can be turned off at any time.
• Disabling usage statistics takes effect immediately. Disabling crash reports takes effect the next time the App starts; this timing is defined by the crash reporting system.

Advertising consent is managed through the consent form Google displays in the App. You can review or change your choice at any time under Settings → Legal & Privacy → Privacy Choices.

Translation is optional. If you prefer that we keep no translation text at all, use your own API key (Section 5).

Server translation requires watching a rewarded ad, and in the EEA, the UK, and other regions where the law requires it, advertising consent. If you decline, server translation is unavailable; you can still use your own API key (Section 5).

5. Service Providers and International Transfers

The App relies on the service providers listed below; as a result, some of your data may be processed outside your country.

• Google (Firebase, Google Cloud, and AdMob). Processes the usage statistics, crash reports, and advertising data described above; hosts our translation server, its database, and its logs; provides anonymous sign-in and security services for the App; and supplies the fonts the App downloads for reading in Arabic, Chinese, Japanese, or Korean. Google acts on our behalf for the data it processes for us. Our translation server and its database are located in the EU; Firebase Authentication runs only in the United States, and Google may process other data in the United States and in other countries where it operates, under transfer safeguards approved by the EU and the UK. Google's privacy policy · Firebase · AdMob
• Google Gemini and Vertex AI — the default translation services. Translation requests are processed on paid plans funded by us; the default service requires no account and no payment from you. Under these paid service terms, Google does not use submitted text to train or improve its models. Google may keep requests for a limited period, solely to detect and prevent abuse, and Vertex AI may cache requests for up to 24 hours, as described in its terms. Gemini API terms · Vertex AI data governance
• A provider you configure yourself (optional). You can instead set the App to use your own API key from Google, OpenAI, Groq, or Z.ai. Translation requests are then sent directly to that provider, authenticated with your key, and that provider's privacy policy governs the processing. Review the provider's terms before adding a key: some providers treat text submitted under a free plan differently from text submitted under a paid plan, and may use it to improve their services.

6. Data Retention

• Crash reports: retained by Google for 90 days, then deleted from its live and backup systems.
• Usage statistics: individual records are deleted after 14 months. The device identifier they are linked to is deleted 14 months after your last use of the App.
• Translation text, direct translation: deleted from our logs after 30 days.
• Translation text, server translation: translations are deleted once your device confirms receipt, and no later than 7 days after the translation ends; full requests of translations that did not complete normally after 30 days.
• Anonymous account: deleted, together with the Firebase Authentication user, about 90 days after you last used server translation. Google then removes the Authentication data from its backup systems within 180 days.
• Translation usage records: deleted after 13 months. When the anonymous account is deleted, the account number is removed from them, so they are no longer linked to your account.
• Rewarded ad verification and translation tickets: deleted 7 days after the translation ends.
• Technical request logs: deleted after 30 days.
• Data on your device: remains until you delete it or uninstall the App.

Deletion after a period ends usually happens within a day but can take longer. Our server database is backed up daily, and backups are kept for 30 days, so deleted server data can remain in a backup for up to 30 more days; if a backup is ever restored, data that should already be deleted is deleted again. Aggregated totals that cannot identify any user — for example, the number of translations performed in a month — are retained indefinitely.

7. Your Rights

If you are in the EEA, the UK, or another country with comparable data protection law, you have the right to:

• access the data held about you
• have it corrected or deleted
• receive a copy in a portable format
• object to or restrict certain processing, including processing based on our legitimate interest
• withdraw your consent at any time

How this works with this App:

• Consent for usage statistics and crash reports can be withdrawn under Settings → Legal & Privacy; advertising consent under Privacy Choices in the same menu. Turning a switch off stops any further collection.
• Data stored on your device is under your direct control: deleting it in the App, or uninstalling the App, removes it completely. We hold no copy.
• Server translation data: if you use server translation, the translations and usage records on our server are linked only to the random identifier of your anonymous account (Section 3). We never ask for your name or email address, and the App does not show you this identifier. An email request therefore cannot normally be matched to your data, and we cannot verify that the sender is the person the data relates to (Articles 11 and 12(6) GDPR). For that reason we do not send copies of server data, and we do not change or delete it, in response to an email request alone, unless you give us additional information that lets us identify your data. We will consider any such information, but we cannot promise it will be enough. We will tell you our reasons within one month of receiving your request. Server data is deleted automatically within the periods listed in Section 6. To stop further processing or to object to it, stop using server translation or use your own API key (Section 5); no new data is then added, and what remains is deleted within those periods.
• Usage statistics, crash reports, and direct translation logs are not linked to a name, email address, or account that we hold, so we are generally unable to locate an individual's records (Article 11 GDPR). They are deleted automatically within the periods listed in Section 6.
• For data held by Google, you can use the links in Section 5. For a translation provider you configured yourself, contact that provider directly under your own account.

For any other request, contact hasanturkylmz@outlook.com. You also have the right to lodge a complaint with the data protection authority in your country.

8. Children

The App is intended for a general audience and is not directed at children under 13, or the higher minimum age that applies in some countries. We do not knowingly collect personal data from children below that age. Because the App includes advertising and analytics, it is not designed to meet the separate parental-consent requirements that apply to services directed at children.

9. Users in Turkey

Under Turkish Personal Data Protection Law No. 6698 (KVKK), the data controller is Hasan Türkyılmaz (Türkiye). The data we process, the purposes, and the legal grounds are described in Sections 2 and 3. Under Article 11 of the Law, you may ask whether your personal data is processed, request information about it and the parties it is transferred to, ask for it to be corrected or deleted, object to a result against you that arises solely from automated analysis, and claim compensation for damage caused by unlawful processing. Send your request by email; we reply within 30 days. How server translation data, which is linked only to a random identifier, is handled is described in Section 7. You may also complain to the Personal Data Protection Authority (KVKK).

10. Changes and Contact

The App is published by Hasan Türkyılmaz (Türkiye), who is responsible for your data. If this policy changes, the date at the top of this page will be updated. For questions, requests, or support, contact hasanturkylmz@outlook.com.