DualSub · Last updated: November 10, 2026
This policy explains what data DualSub processes when you use its bilingual subtitles, contextual dictionary, review cards, listening courses, local video player, rewarded ads and optional subscriptions.
Privacy questions and deletion requests can be sent to dualsubenglish@gmail.com. The dedicated deletion procedure is available at Delete account and data.
Saved vocabulary, review scheduling, course progress, preferences and local video playback state are primarily stored on your device. Local videos selected with Android's file picker and media processed by the current on-device transcription option are not uploaded by the distributed app. Removing the app or clearing its storage deletes this local copy unless you exported a backup.
| Data | When | Purpose and recipients |
|---|---|---|
| Name, email, profile photo and Google user identifier | Only if you choose Sign in with Google | Authentication, account display and linking the subscription status. Processed by Google and RevenueCat. |
| YouTube subscriptions, channel information and search requests | When you connect YouTube or use YouTube search | Show your channels, videos and search results. Processed through YouTube API Services. |
| Learning languages, screens and features used, video identifiers, playback milestones and interaction events | During normal app use | Product analytics, recommendations, reliability and retention analysis through Firebase Analytics. Analytics events do not include entered search text, subtitle sentences, selected words, names or email addresses. |
| Device or app identifiers, approximate location derived from IP, ad interactions and diagnostics | When a free user requests a rewarded ad, subject to the applicable consent flow | Advertising, ad measurement, fraud prevention and diagnostics through Google AdMob. |
| Purchase history and subscription status | For every installation where purchase status must be checked | Enable, restore and validate Premium access through Google Play Billing and RevenueCat. |
| Selected word, subtitle sentence, nearby subtitle context and language pair | Only when the cloud contextual dictionary is used | Generate a contextual definition or translation through DualSub's service providers, which may include OpenAI. The complete video is not sent for this request. |
| Voice input | Only when you start a spoken-answer exercise | Convert your answer to text using the speech recognition service available on the device. Processing may be local or performed by the device provider. |
| Technical errors and diagnostics | When a failure occurs | Diagnose subtitle, playback, network and app reliability problems through Firebase Analytics and, for rewarded ads, AdMob. |
Earlier DualSub releases use YouTube API Services. In those releases, public search and browsing use the YouTube Data API. Videos are played through YouTube's embedded player. Connecting your Google account is optional for public browsing; it enables a read-only view of your subscriptions.
youtube.readonly, DualSub reads your subscribed
channels and related video/playlist information. Google Sign-In provides the authentication
information described in section 3. Authorization credentials are handled by Google's sign-in
service and used to authenticate requests; they are not included in analytics events.The updated YouTube player supplies separate study transcripts only for material with documented reuse permission. Other available captions remain in the native YouTube player. This update removes hidden playback and external transcript-mirror requests. The current releases described above do not open this player. Older installed versions may still request a video's identifier and language from the transcript providers configured in those versions; update DualSub to use the revised player. DualSub's updated server no longer extracts those tracks.
DualSub uses these data to display search results, your channels and video lists, show the correct title and thumbnail, open selected videos, and restore your selected learning activity. Temporary feed and search caches are stored on your device to reduce loading time and repeated requests. In earlier releases, an optional TV link sends the selected channel/video list to DualSub's Firebase/Google Cloud service so it can appear on your linked TV. The app stops displaying this copy after 30 days from its actual synchronization; watching does not renew it. A daily server maintenance task removes disposable TV lists once their actual synchronization is more than 29 days old, without removing the account, TV pairing, purchase, vocabulary or examples. The seven-day deadline below applies to requests to remove this YouTube user data. In those earlier releases, Google receives API and embedded-player requests. DualSub's Firebase analytics receives video identifiers and app interaction events as described in section 3; it does not receive your full subscription list, search text or authorization credentials. Our optional cloud language tools receive the selected text/context described in section 3, not your subscription list or tokens.
We do not sell YouTube user data. Access inside DualSub is limited to the functions described here and to service/support personnel where necessary to resolve a request. Google, Firebase and the other recipients listed in section 5 process only the data needed for their stated functions.
This scope is read-only. DualSub cannot subscribe to or unsubscribe from channels, upload or edit videos, delete YouTube data, rate content, or post comments on your behalf.
Search pages are refreshed after 10 minutes in memory. The persistent public-request cache normally refreshes after 30 minutes and may reuse a response for up to 24 hours during an outage or quota limit. Subscription feeds normally refresh after 10 minutes; their fallback cache expires after 30 days. Shorts queues expire after 12 hours. Expired cache records are removed when the app next runs or accesses the cache; the app cannot execute cleanup while the device or app is stopped. Signing out removes disposable subscription-feed and Shorts caches from that device. Catalog title/thumbnail metadata is refreshed through the official Data API or withheld after 30 days; changing a catalog file or downloading a cached copy does not renew that deadline.
You can revoke DualSub's Google access at Google Account permissions and request deletion of YouTube-related data held by DualSub through Delete account and data or dualsubenglish@gmail.com. We process requests to delete stored YouTube user data as soon as possible and within 7 calendar days of the request, verifying ownership promptly within that period. Deleting data held by DualSub does not delete your YouTube account or change your subscriptions or other data held by YouTube. Your saved vocabulary and examples can be managed separately in DualSub.
Use of YouTube features is subject to the YouTube Terms of Service and Google Privacy Policy.
We do not sell personal data. Providers process data only for the functions described above and under their applicable terms.
Premium users do not receive DualSub ads. Free users may voluntarily request a rewarded ad to unlock a limited action. Where required, Google's consent form is shown before AdMob is initialized. Available privacy and ad choices can be reopened from Profile > Privacy.
Optional features such as Google sign-in, rewarded ads, cloud dictionary requests and voice answers are initiated by you. Core analytics and purchase-status checks are used for service operation, security, product improvement and contractual access management. Android permissions are requested only when the related feature needs them.
Local data remains until you delete it, clear app storage or uninstall the app. Provider-side data is kept according to the configured retention period, legal obligations and the provider's policy. Purchase records may need to be retained for accounting, fraud prevention and subscription support. Aggregated or de-identified analytics may not be attributable to an individual deletion request.
You can request deletion of your DualSub account link and associated identifiable data from inside the app at Profile > Privacy > Delete account and data, or through the web deletion page. YouTube user-data deletion requests are handled within 7 calendar days of the request, with ownership verification performed promptly within that period, as described in section 4.
Data sent by the app uses encrypted HTTPS/TLS connections. Providers may process information in countries other than yours and apply the safeguards described in their privacy documentation. No internet transmission or storage method can be guaranteed to be completely secure.
DualSub is not directed to children under 13. If you believe a child submitted personal information, contact us so that it can be removed.
DualSub guarda principalmente en el dispositivo las palabras, repasos, progreso, ajustes y estado de los vídeos locales. Transmite a proveedores los datos estrictamente necesarios para iniciar sesión, mostrar YouTube en versiones anteriores, medir el uso, validar Premium, ofrecer anuncios recompensados y resolver definiciones contextuales.
El inicio de sesión, los anuncios, las respuestas por voz y el diccionario contextual en la nube son funciones opcionales. No vendemos datos personales. Puedes solicitar el borrado desde Perfil > Privacidad > Eliminar cuenta y datos o desde esta página.
We may update this policy when legal, technical or product practices change. The date above identifies the current version.