Privacy Policy

Last updated: July 2026

Dubstack reads subtitle information on the Netflix or YouTube video you are watching so it can display two caption tracks and handle lookups. It does not build or send us a history of what you watch.

Data used in Chrome

Dubstack handles the current video URL, available subtitle tracks, subtitle text, and your interactions with its controls. Your settings, saved words and scene context, local lookup cache, activation choices, and usage counter are stored in Chrome extension storage. Free on-device translations use Chrome's translation capabilities when available.

This local information is used only to provide Dubstack's subtitle and lookup features. It is not sent to Dubstack for analytics, advertising, or profiling.

Premium lookups

When you choose Explain for the first time, that deliberate action authorizes Premium processing for that and future lookups on this installation. Dubstack sends the selected phrase, nearby subtitle line, language pair, and an anonymous installation identifier over HTTPS to Dubstack's Cloudflare Worker. The phrase and line are passed to Anthropic to write the requested translation or explanation. Before that first Explain request, automatic fallback does not send subtitle text. Your payment email and current video URL are not included in the request.

Generated answers may be cached for up to 90 days so identical lookups do not repeatedly call the model. Cache keys are one-way hashes of the lookup inputs.

Payments

Checkout and billing are handled by Stripe. Dubstack never receives or stores your card details. Stripe sends Dubstack the payment email, customer or subscription identifiers, subscription status, and the anonymous installation identifier so Premium can activate, recover on another browser, and stop after cancellation.

Retention and deletion

Local data remains until you clear it or uninstall Dubstack. Short-lived usage and rate-limit records expire automatically. Premium entitlement records remain while needed to provide or recover paid access. To delete server-side entitlement records after cancellation, email [email protected] from the payment email.

Service providers

Cloudflare hosts the Premium API, Anthropic generates requested answers, and Stripe handles billing. They process only the information needed for those jobs under their own privacy and security terms.

Chrome Web Store Limited Use

Data obtained through Chrome extension permissions is used only to provide or improve Dubstack's visible subtitle and lookup features. It is not sold, used for personalized advertising, used to assess creditworthiness, or transferred for unrelated purposes. People do not read subtitle or lookup data except when you explicitly share it for support, when required for security, or when required by law.

Contact

Questions and privacy requests can be sent to [email protected].