Learn freely, understand your data.

When signed out

Your current step and graphics preferences are stored in your browser. Saving lessons and downloading Vietnamese HTML require sign-in or a free account. Opening a lesson does not create an account. Clearing this website's browser data removes these local records.

When signed in

Tài Nguyên Số authenticates your account. Lab receives an account identifier and the necessary display information, uses a separate session, and stores progress and saved lessons in a separate learning database. Lab does not store your password or Google authentication credentials. Bilingual sentences, terms, notes, tags, review schedules and lesson plans are stored in the separate Lab database. Notebook content is visible only to its owning account.

Notebook and recovery

You can hide and restore individual items or lesson plans. An exported HTML lesson plan contains your selected items; check personal content before sharing the file. Clearing progress and saved lessons on the account page does not delete your Study notebook.

Deleting learning data

On the account page, you can clear your own synchronized learning data in Lab. This does not delete your Tài Nguyên Số account, content, orders or access rights.

Connections and logs

Cloudflare infrastructure handles network requests and the technical logs needed to operate the service. Simulation state is not sent every frame. Downloaded HTML works independently and contains no account sign-in information.