Privacy Policy

Last updated: July 2026

Summary

Language Den shows no ads and does not sell your data
We run first-party product analytics (Ahoy) on our own servers so we can understand sign-up and learning funnels. We do not use third-party analytics vendors such as Google Analytics or Mixpanel
Your vocabulary data is stored on our servers and is never shared for advertising
We use third-party AI and image APIs to power built-in features. Only the minimum data needed is sent
You can delete your account and all associated data at any time

Data we store

When you create an account, we store:

Account information — your email address and a hashed password (we never store your password in plain text). If you sign in with Google, we store your name and Google account identifier instead.
Vocabulary data — the words, translations, flashcards, review history, and quick notes you create within the app.
Review history — timestamps and ratings from your review sessions, used to calculate your spaced repetition schedule.
Session data — a session token stored in a secure cookie so you stay signed in.
Product analytics — first-party visit and event records described under Analytics below.

Third-party services

AI flashcard generation

When you generate flashcard content or request a translation, Language Den sends the word and its translation to an AI language model API to produce the output. No personally identifiable information is included in these requests.

Unsplash (image search)

When you search for images to attach to a flashcard, your search query is sent to the Unsplash API. No account information is included. Chosen photos are hotlinked from Unsplash’s CDN (we store the image URL and photographer attribution, not a private copy of the file). See Unsplash's Privacy Policy and the Unsplash API Guidelines.

Stripe (payments)

Subscription payments are processed by Stripe. Language Den never sees or stores your payment card details. See Stripe's Privacy Policy.

Analytics and advertising

Language Den contains no advertising SDKs and does not show you ads. We do not sell your data. We do not use third-party analytics products such as Google Analytics, Mixpanel, or PostHog.

We do use Ahoy, a first-party analytics library that runs on Language Den servers. Tracking is server-side only. We do not load third-party analytics JavaScript in your browser.

Ahoy records:

Visits — approximate timing, landing page, referrer, UTM parameters when present, browser and device details from the user agent, a masked IP address, and your user id after you sign in
Product events — funnel events such as registration, onboarding steps, adding words or sources, completing a review session, and subscription checkout or activation

IP addresses are masked before storage. We do not geocode visits. This data stays in our database and powers internal dashboards so we can see where people get stuck and whether the product is working. It is not sold or shared for advertising.

Ahoy sets first-party cookies (ahoy_visitor and ahoy_visit) so we can recognize returning browsers for these visit records. Those cookies are not used for cross-site advertising.

Your rights (GDPR & CCPA)

You have the right to access, correct, export, or delete the personal data we hold about you. To exercise any of these rights:

Export your vocabulary: Download a CSV from the Words page (Export CSV) or Profile & Settings → Data export. Each download covers your active study language.
Delete your account: Go to Profile & Settings inside the app. Deleting your account permanently removes all your data from our servers.
Other requests: Email us at hey@languageden.com and we will respond within 30 days.

Data retention

We retain your data for as long as your account is active. When you delete your account, all associated data is permanently deleted from our systems within 30 days.

Children

Language Den is not directed at children under 13. We do not knowingly collect personal information from children.

Changes to this policy

We may update this policy as the app evolves. Significant changes will be noted on this page with an updated date. Continued use of Language Den after changes constitutes acceptance of the updated policy.

Contact

Questions about this privacy policy? Email us at hey@languageden.com.