Privacy Policy
Last updated: 2026-05-06
What we collect
When you use CaptionTwin we receive: (a) audio you record from your microphone, streamed to our transcription provider; (b) the resulting text transcripts and AI-generated notes; (c) usage counters such as total recording time; (d) a random anonymous identifier stored in your browser's localStorage so we can show you your own past sessions. If you sign in with Google, Apple, or email we additionally receive your email address. If you upgrade to a paid plan we receive a Stripe customer ID.
Account & sign-in
Sign-in is optional for free use, and required only for the paid tiers (Pro and Unlimited) so paying customers don't lose access if they switch devices. We support Google, Apple, and magic-link email via Supabase Auth. We collect nothing more than your email address — no contact lists, no profile photo, no social-graph data. You can sign out anytime from the sidebar; your local sessions on that device stay accessible. To delete your account entirely, see “Your rights” below.
How we use it
Audio is streamed in real time to Deepgram for transcription and is never stored on our servers — only the resulting text transcript is. When you finish a session, the transcript and AI-generated notes are saved to our Postgres database (Supabase, US East). We use Google Vertex AI (Gemini) to translate transcripts and generate study notes. We may use PostHog to analyze aggregate usage patterns.
Who we share with
We share data only with subprocessors strictly necessary to operate the service: Deepgram (live transcription), Google Cloud / Vertex AI (translation and notes), Supabase (database hosting), Stripe (payments), Vercel (hosting), and PostHog (analytics). We do not sell your data.
Your rights
You can delete any session at any time from the session detail page; deletion is immediate and removes the transcript, notes, and any stored audio. To delete your account entirely, email hello@captiontwin.com.
Cookies
We do not set advertising cookies. We use the browser's localStorage for an anonymous user identifier. When you sign in, Supabase Auth sets HttpOnly session cookies (used only to keep you signed in) and Stripe sets its own cookies during checkout.
Contact
CaptionTwin is operated by Zendon Labs LLC, a limited liability company based in Illinois, United States. Questions? Email hello@captiontwin.com.