Privacy policy
Last updated: October 17, 2026
Who we are
Nihongo Learn is an independent project operated by Daniel Hernández (Dominican Republic), the data controller for this website. Contact for anything in this policy: [email protected]. It covers the nihongolearn.app website and the Nihongo Learn browser extension.
The extension
The extension stores everything — decks, cards, review progress and settings — locally in your browser and sends none of it to our servers. If you connect it to your account (optional), it checks in with nihongolearn.app once a day so it can show your Premium; that check carries only the browser’s connection, never your decks. Dictionary and stroke-data lookups (Jisho, JMdict, Wikimedia, KanjiVG) go directly from your browser to those services and are governed by their own policies.
Data this website collects
Account: your email address, used only to sign you in (Google or magic link) and never shown publicly. Public profile: the handle and display name you choose. Community content: the decks you publish, your star ratings and your reports — published decks are public by definition. Launch waitlist: your email and language, used solely to send one launch announcement. Premium: if you buy it, Polar (merchant of record) processes the payment; we receive only your email and the purchase status. Connected browsers: if you connect the extension to your account, the name of each browser (e.g. “Brave · macOS”), when you connected it and when it last checked in — you can disconnect any of them from your Profile, and one that does not check in for 60 days disconnects by itself.
Why we process it (legal bases)
We process account and community data to provide the service you request (performance of a contract), the waitlist with your consent (withdrawable at any time), and moderation and abuse-prevention data (reports, publication limits) under our legitimate interest in keeping the community safe. We do not sell personal data, show ads or build profiles of you.
Cookies
The site uses only strictly necessary cookies: the session cookies that keep you signed in. There are no advertising or tracking cookies, and no analytics tools — which is why you see no cookie banner.
Where your data lives
We rely on trusted processors to run the service: Supabase (database and authentication), Railway (hosting; it keeps technical request logs, such as the IP address, for a limited time to run and protect the service) and Google (optional sign-in). Their servers may be located in the United States or the European Union; transfers are covered by these providers’ standard contractual safeguards.
How long we keep it
Account and profile data: until you delete your account. Published decks: until you or moderation remove them. Reports: up to 12 months. Waitlist: until the launch email is sent or you ask to be removed. Residual copies in backups are purged on a short cycle.
Your rights
Depending on where you live (GDPR, LGPD, APPI and similar laws) you may request access, correction, deletion, portability, restriction or objection, and withdraw consent at any time by writing to [email protected]. You may also lodge a complaint with your country’s data-protection authority. Deleting your account removes your email, profile and ratings; your published decks are deleted with it unless you removed them earlier.
Minimum age
Nihongo Learn is not directed at children under 13. Creating an account and publishing content requires being at least 16, or the minimum age for digital consent in your country if higher.
Changes
We may update this policy as the service evolves; the date above always reflects the current version and significant changes will be highlighted on the site. Questions: [email protected].