the short version
- On the free plan the audio is not stored anywhere — only the resulting text transcript is.
- Stored audio (paid plans only) is kept for as long as you stay on Basic or Plus. If your plan ends, the audio is kept for 30 more days so you can download it.
- We do not sell your data.
- We use Google Ads cookies only to measure whether our ads work; you can opt out.
- You can delete any session at any time from the session detail page; deletion is immediate.
What we collect
When you use CaptionTwin we receive: (a) audio you record from your microphone or a browser tab, 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; (e) when you record without an account, a one-way hash of your IP address that changes every day, used only to count how many trial identities come from one network so we can spot abuse of the free trial — we never store the IP address itself and delete these hashes after 30 days. 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, and the audio of your paid recordings is stored so you can replay it (see “How long we keep audio”).
Account & sign-in
You can try CaptionTwin without an account for the first 30 minutes of recording. After that, signing in is required to keep using the free trial (3 hours in total, including those 30 minutes) and for the paid tiers (Basic and Plus), so that your transcripts, notes and any paid plan follow you across 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 from your browser to one of our transcription providers, Deepgram or Soniox depending on the recording (see “Who we share with”), to produce the live transcript. When a recording uses Soniox, Soniox also returns a draft translation into your target language while you record; the final translation still comes from Google Vertex AI (below). On the free plan the audio is not stored anywhere — only the resulting text transcript is. On the paid plans (Basic and Plus) the audio of each recording is uploaded after the session to our storage provider (Supabase Storage, US East) so you can replay it alongside the transcript. When you finish a session, the transcript and AI-generated notes are saved to your account in 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. We use Google Analytics to measure website visits, page types and engagement. Our Google Analytics events use generic page titles and paths, with recording and source identifiers removed. We do not send your audio, transcripts, notes, email address or URL query parameters to Google Analytics. We use the Google Ads tag to measure whether our ads lead to sign-ups and paid subscriptions. When you complete a purchase, we send Google the order ID, amount and currency — no email address, transcripts, audio or notes. We use it for measurement only and have turned off ad personalization (remarketing) signals in our tag.
How long we keep audio
Stored audio (paid plans only) is kept for as long as you stay on Basic or Plus. If your plan ends, the audio is kept for 30 more days so you can download it, and then deleted automatically — never sooner than the retention window promised at upload. New uploads on either paid plan have a minimum 90-day window from upload; older recordings keep their original window. The transcript and notes stay on your account until you delete the session. You can download a recording's audio, or delete a session including its audio, at any time.
Emails we send
We email your sign-in links and messages about your account. If you have signed in and are on the free plan, we may also email you occasional product news and offers for our paid plans. Every one of those includes an unsubscribe link; unsubscribing stops them without affecting your account or the sign-in and account emails. We never put your recordings, transcripts or notes in these emails. Emails are sent through Resend.
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 support@captiontwin.com.
Your California privacy choices
We do not sell personal information. We use advertising measurement cookies as described above. California residents may opt out of the sharing of personal information for cross-context behavioral advertising by blocking advertising cookies as described above or emailing support@captiontwin.com. We do not knowingly sell or share data of consumers under 16.
Contact
CaptionTwin is operated by Zendon Labs LLC, a limited liability company based in Illinois, United States. Questions? Email support@captiontwin.com.