Privacy Policy

This Privacy Policy explains what information S39 Labs ("we") collects when you use LectureVoice (the "Service"), how we use it, who helps us process it, and how you can delete it. We collect only what we need to turn your slides into narrated videos.

1. Information we collect

• Account information: your name and email address. If you sign up with a password, we store only a secure hash of it, never the password itself. If you sign in with Google, we receive your Google account ID, name, email address and profile picture from Google.
• Your content: the slide decks you upload, the narration scripts, your voice recordings (including long recordings for HD voices), written transcripts of those recordings, HD voice models trained from your recordings, and the audio, video and subtitle files we generate for you.
• Consent records: when you create an HD voice, we record that you confirmed you have the right to clone that voice.
• Technical information: the IP address and browser information of your signed-in sessions, and server logs. We use these to keep your account secure, prevent abuse and fix problems.
• Donations: if you choose to donate, PayPal handles the payment. We receive a confirmation such as the amount and a transaction reference. We never see or store your card or bank details.

We do not use advertising, tracking or analytics cookies. We keep a sign-in token in your browser's local storage so you stay signed in; signing out removes it.

2. How we use your information

• To run the Service: convert your slides, write scripts, clone your voice, synthesise narration and render your videos.
• To use the transcript of your voice recording as a style reference, so the scripts sound like the way you speak.
• To send account emails, such as email verification and password resets.
• To keep the Service secure and working, and to respond to your requests.

We do not sell your information and we do not use it for advertising.

3. Your voice

Voice recordings are personal, biometric information, and we treat them that way. Your recordings and HD voice models are used only to create narration in your own projects. They are never shared with other users and never used to build voices for anyone else. Every audio file we generate carries an inaudible watermark that identifies it as AI-generated.

You must only upload a voice that is yours, or that you have clear permission to clone. See our Terms of Service.

4. Service providers we use

We rely on these providers to run the Service. Each processes data only to provide its part of the Service:

• Vercel — hosts the website you use.
• Amazon Web Services (AWS) — runs our application server (United States).
• Modal — runs the processing jobs: slide conversion, transcription, voice cloning and training, speech synthesis and video rendering (United States).
• Neon — hosts our database: your account, project and voice records (United States).
• Cloudflare R2 — stores your files: slides, recordings, voice models, audio and videos.
• Google (Gemini API) — writes the narration scripts. For each slide we send the slide image and text, and the transcript of your voice recording as a style reference. We currently use Google's free Gemini tier, under which Google may use submitted content to improve its products (see Google's Gemini API terms).
• Google Sign-In — only if you choose to sign in with Google.
• Resend — sends account emails.
• PayPal — processes optional donations.

Your information is mainly processed and stored in the United States. If you use the Service from elsewhere, your information is transferred there.

5. How long we keep it, and deleting it

• We keep your information while your account is active, until you delete it.
• Deleting a voice removes its recordings, its HD voice model and its previews.
• Deleting a project removes its uploaded slides, scripts, audio, video and subtitles.
• Deleting your account: email us from your account's email address at contact@s39labs.com and we will delete your account and all of its content.

Copies may remain for a limited time in our providers' backups and logs before they are overwritten.

6. Security

All traffic is encrypted (HTTPS), passwords are stored as secure hashes, and each account can only access its own projects, voices and files. No system is perfectly secure, but we work to protect your information.

7. Your rights

Depending on where you live, you may have the right to access, correct, export or delete your personal information, or to object to how we use it. To make a request, contact us at contact@s39labs.com.

8. Children

The Service is not intended for children under 16, and we do not knowingly collect their information.

9. Changes to this policy

We may update this Privacy Policy. We will post the new version here and update the "last updated" date above.

10. Contact

For privacy questions, contact S39 Labs at contact@s39labs.com.