1. Information We Collect
When you use CaptionLab, we collect minimal operational information required to deliver subtitle synchronization:
- Account Information: When signing in with Google OAuth, we receive your name, email address, and profile picture avatar.
- Project Configuration: Caption text, styling presets, font choices, and watermark coordinates are saved locally to your browser storage (IndexedDB / LocalStorage) or synced to your private account workspace.
- Technical Diagnostics: Anonymized error logs, browser version, and rendering performance statistics to monitor app stability.
2. Local-First Video Processing
Unlike traditional cloud rendering farms that require uploading multi-gigabyte video files to third-party servers, CaptionLab uses browser-native HTML5 Canvas and WebCodecs technologies:
- Your video frames are decoded, drawn, and burned directly on your local device hardware.
- Raw video files remain on your machine during editing and rendering.
- Exported MP4 videos and SRT files are saved directly to your local file system.
3. Audio Transcription & Speech Data
To generate word-level timestamps and karaoke highlights, the audio track of your video is streamed securely via encrypted TLS 1.3 channels to our transcription service:
- Audio streams are processed in memory solely to compute acoustic timecodes.
- No human listens to your audio files.
- Audio buffers are discarded immediately following transcription completion.
4. Data Security & Encryption
We apply industry-standard cryptographic protections to safeguard your account:
- All HTTP traffic is enforced over HTTPS with HSTS preloading.
- Personal access tokens and API keys are stored in secure browser local storage and never exposed in client logs.
- Database backups are encrypted at rest with AES-256.
5. Your GDPR & CCPA Rights
Under international privacy regulations (including GDPR and CCPA), you hold the right to access, rectify, or permanently delete any stored project metadata or account details. You can request complete account deletion at any time by contacting us at privacy@captionlab.io.