Privacy Policy

Information we collect

Account information. Your email address (required for sign-in), and optionally a preferred name. We use passwordless magic-link sign-in, so we never store a password.

Learning profile. The language you are studying, your level and prior exposure, your native language, and any topic you choose for a practice session, so the tutor can tailor practice to you.

Learning activity. Your flashcard reviews and scheduling state, your progress through stories and lessons, and the text transcript and summary of each voice tutor session, including corrections of mistakes you make while speaking. We use these to schedule reviews, target your weak spots, and measure progress.

Voice audio is not stored. When you speak to the tutor, your audio is sent for transcription and then discarded. We keep only the resulting text transcript, never the audio recording.

Billing information. If you subscribe, our payment processor (Stripe) handles your card details. We never see or store your full card number. We store your subscription status, plan, and renewal or trial dates.

Usage and diagnostics. Basic product analytics (which features you use, counts and timings), error reports, and an estimate of the AI cost of your sessions, so we can keep the service running and affordable. We also record a one-time, first-touch record of how you found us (for example referral source or campaign parameters in the link you arrived from). Our analytics live in our own database. We do not use third-party advertising or cross-site tracking.

How we use your information

To provide and personalize the product: schedule your reviews, run the voice tutor, generate stories and lessons, and adapt to your level and the topics you choose. To process payments and manage your subscription. To keep the service secure and reliable, including rate limiting and abuse prevention. To understand how the product is used so we can improve it. To contact you about your account, such as sign-in links and important service notices.

We do not sell your personal information, and we do not use your content to train our own advertising or unrelated models.

Service providers we share data with

We share only what each provider needs to do its job:

• OpenAI processes your speech (speech-to-text), generates the tutor's replies, synthesizes speech (text-to-speech), and analyzes session transcripts. Under OpenAI's API terms, data sent to their API is not used to train their models and is retained only briefly (currently up to 30 days) for abuse monitoring before deletion.
• Stripe processes payments and stores your card details under its own privacy terms.
• Resend sends your sign-in emails.
• Neon and Vercel host our database and application.
• We may use alternative speech or language providers to improve latency or quality. When enabled, they process the same kinds of session data as OpenAI under their own terms.

We may also disclose information if required by law, or to protect the rights, safety, and security of our users and the service.

How long we keep your data

We keep your account and learning data for as long as your account is active. Operational records are pruned automatically: detailed product analytics after about 90 days, AI cost records after about 90 days (after which only anonymized daily totals remain), and logged corrections after about 90 days once resolved, or at most one year. When you delete your account, we remove your personal data and learning history, and any remaining analytics are anonymized so they can no longer be tied to you.

Your rights and choices

You can access and update your profile in Settings. You can download a copy of your data and permanently delete your account from Settings at any time. Deleting your account erases your learning history and personal information from our systems. Depending on where you live, you may have additional rights under laws such as the GDPR or CCPA, including the right to access, correct, export, or delete your personal data, and to object to certain processing. To exercise any of these, use the in-app tools or contact us at [email protected].

Cookies

We use a single first-party cookie to keep you signed in. We do not use third-party advertising cookies or cross-site trackers, so there is nothing to consent to beyond keeping you logged in.

Children

Kotobia is not directed to children under 16, and we do not knowingly collect personal information from them. If you believe a child has provided us data, contact us and we will delete it.

International users

We operate the service and our providers process data in the United States and other countries. By using Kotobia you understand your data may be processed in those locations.

Changes to this policy

We may update this policy as the product evolves. We will revise the date above and, for material changes, give notice in the app or by email.

Contact

Questions about privacy? Email us at [email protected].