Shiberu ("we", "us") provides the Shiberu language-learning app, the Shiberu browser extension and the Shiberu Sync add-on for Anki, and is responsible for (the controller of) the personal data described here. For any privacy question, or to exercise your rights (section 9), email [email protected]. Shiberu is operated by Stratford Oakham EOOD ("Stratford Oakham" Ltd.), a company registered in Bulgaria (UIC/EIK 207500501, VAT BG207500501), registered office: ul. Racho Dimchev 1, entr. A, fl. 2, apt. 9, Sredets, 1000 Sofia, Bulgaria.

To create an account we collect a username, your email address and a password, which is stored only as a secure hash. If you use Sign in with Google, Google sends us your email address and a token that confirms it; we never receive your Google password. On the web, the Google button loads Google's sign-in script from Google.

We email you only about your account: verification codes, password resets, account-deletion codes and, if you turn them on, study reminders (at most one per study day, each with an unsubscribe link). We do not send marketing emails.

Optional profile details: a display name, a bio, a link to an avatar image, and your native, target, interface and explanation languages. They personalise the app and, if your profile is public, appear on your profile page.

Shiberu stores what you put into it so that it works on every device you sign in on:

In the mobile app, decks you download for offline study and reviews you do offline are kept on your device and sent to your account when you are back online. Study reminders on your phone are local notifications scheduled on the device; we do not collect a push-notification token or any advertising or device ID.

Everything else, including your own decks, cards, reviews and documents, is visible only to you.

Reports and blocks. If you report a comment, deck or profile, we store your account, the reported item (with a copy of its text at the time), the reason and any note you add, so our team can review abuse. If you block someone, we store the block so we can enforce it. A report is kept as the record of our review until either account is deleted; a block is kept until you unblock the person or either account is deleted. The person you report is not told who reported them.

AI explanations, translations, text-to-speech, text recognition for imported documents and answer grading run on Shiberu's own self-hosted models, on our own servers. The text you send to these features is not passed to OpenAI, Google, Anthropic or any other third-party AI or translation provider.

To keep these features fast, results such as word analyses, explanations, translations and generated audio are cached and shared across all users. These shared caches are keyed only by the text itself (and its language) and contain no account data, so they cannot be traced back to you.

We use a few service providers that process data on our behalf, only to run Shiberu:

Some of them may process data outside your country, including in the United States. Where the GDPR applies, they do so under the safeguards it requires, such as the EU Standard Contractual Clauses.

We do not sell your personal data, and we do not share it with anyone for their own purposes, including advertising. There are no advertising, analytics or crash-reporting SDKs in the app, the extension or the add-on. To see whether new learners get started, our own servers record a few first-time milestones linked to your account (signed up, finished onboarding, first review, first study session, first card mined, first import). The public website counts page visits only as anonymous daily totals.

Wherever you live, and in particular under the GDPR in the EU/EEA and the UK, you can access, correct, export or delete your personal data, object to or restrict its processing, and withdraw your consent. You can do most of this yourself in the app (edit your profile, export decks to Anki, delete content or your whole account). For anything else, email [email protected]; we answer within one month.

We process your data to provide the service you signed up for (performance of a contract), with your consent where we ask for it (for example camera or microphone access, or reminder emails), and for our legitimate interest in keeping Shiberu secure and understanding whether it works for new learners.

If you think we have handled your data wrongly, please contact us first. You also have the right to complain to the data protection authority where you live or work.

The Shiberu browser extension sends the subtitle text of what you study to Shiberu's servers to make words clickable and explainable, saves the cards you choose to mine (optionally with a screenshot and a short audio clip), syncs your word statuses, and may send anonymous diagnostic events that contain no content (you can turn them off). It works from the subtitle text and never decrypts, records or downloads the video. The full details are in the extension privacy policy, which is part of this policy.

The Shiberu Sync add-on runs inside desktop Anki and talks only to https://shiberu.app over HTTPS, and only while you are paired or signed in. For the decks you link, it sends:

To recognise renamed or deleted decks, it sends the names and ids of all decks in the collection. It also sends the Anki profile name (as the device label), a random collection id, and the add-on and Anki versions.

It sends nothing from decks you have not linked, nothing about your AnkiWeb account, and no analytics.

Pairing stores a revocable device key in the add-on's folder; unpair it at any time under Profile ▸ Anki sync. Synced data is kept in your Shiberu account until you delete it or close your account.

Shiberu is not directed at children under 13 (or the minimum age in your country). We do not knowingly collect data from children; if you believe a child has given us personal data, contact us and we will delete it.

If we make material changes to this policy, we will update this page and its "Last updated" date and, where appropriate, tell you in the app.