Privacy Policy

Last updated July 24, 2026

KnowDDI collects only the information needed to provide free member access, keep accounts secure, and review community suggestions.

Information we collect

When you continue with Google, Google shares basic profile information such as your name, email address, profile image, and account identifier. When you continue by email, KnowDDI stores the address you submit and sends a single-use sign-in link to that inbox. KnowDDI stores account and session records so you can sign in. We do not receive or store your Google or email password.

When you suggest a lesson or correction, we store the content you submit with your account name, email, and user identifier. We also process connection and browser information for session security and abuse prevention. Suggestion rate limiting stores a one-way hash derived from the connection address.

How information is used

Account data is used to authenticate you, maintain your session, attribute private submissions, respond when follow-up is useful, and protect the service. Suggestions are reviewed privately and are never published automatically. KnowDDI does not sell personal information.

Storage and retention

Account and suggestion data is stored in a private database on the KnowDDI server. Email sign-in tokens are stored as one-way hashes, can be used once, and expire after 15 minutes. Sessions normally expire after 30 days. Account records are retained while the account is active, and suggestions are retained while they remain useful to the editorial process or are required for security and legal purposes.

Third-party services

Google provides social authentication under its own privacy terms. KnowDDI’s configured email delivery provider processes the destination address and sign-in message to deliver passwordless links. Embedded lessons use YouTube’s privacy-enhanced domain; YouTube may process information when you play a video. Linked standards and external resources are governed by their respective sites.

Your choices

You can sign out at any time. To request access to or deletion of your KnowDDI account data, email privacy@knowddi.com. Deleting a KnowDDI account does not delete your Google account or email inbox.

Changes

This policy may be updated as KnowDDI evolves. Material changes will be reflected on this page with a new review date.