Privacy Policy

Last updated: May 2026

1. No Data Collection

SyncFlow is a fully client-side application. All video and subtitle processing happens entirely within your web browser using JavaScript. No user tracking or analytics scripts (page views via Google Analytics only — anonymous, no personal data). We do not:

• Upload your files to any server
• Store your files in any database
• Track your usage or behavior
• Collect personal information
• Track your personal behavior across websites

2. Where Processing Happens

When you upload a video or subtitle file to SyncFlow, the file is read by your browser and processed locally. Your original video and subtitle files never leave your computer. This means:

• Your video content stays private
• Your subtitle files are never accessible to us or anyone else
• Offset adjustment, drift calibration, manual editing, and export all work without any network requests

Cloud-proxied features (require internet):

• Auto-Transcribe: Audio is extracted locally, sent through a Cloudflare Worker to Groq's Whisper-large-v3-turbo API, and the transcription is returned. Audio is not stored.
• AI Translation: Subtitle text is sent through a Cloudflare Worker to Groq's Llama-3.3-70B API, and the translation is returned. Text is not stored.

3. Cookies & Analytics

SyncFlow itself does not set functional or tracking cookies. We use Google Analytics (gtag.js) to collect anonymous page-view statistics. Google Analytics may set first-party analytics cookies. No personal data is collected. You can opt out via Google's opt-out tool.

The only local storage SyncFlow uses is for your theme preference (dark/light mode), auto-saved subtitle data, session recovery information, and application preferences. This data stays in your browser and is never transmitted.

4. Hosting Provider

SyncFlow is hosted on Cloudflare Pages/Workers. Cloudflare may process basic HTTP request data (IP address, browser type, request timestamp) as part of standard web serving operations. This data is subject to Cloudflare's Privacy Policy. We do not have access to this data and do not use it for any purpose.

5. Third-Party Services

SyncFlow loads the Google Fonts 'Outfit' and 'Plus Jakarta Sans' from Google's servers when you load the page. Google's use of data is governed by Google's Privacy Policy.

6. AI Transcription & Translation (Cloud-Proxied)

SyncFlow offers optional AI features that use cloud-based APIs through a secure proxy. Here is exactly how data flows:

Auto-Transcribe (Whisper-large-v3-turbo via Groq)

1. Your video's audio track is extracted locally in your browser
2. The audio is sent to a Cloudflare Worker, which forwards it to Groq's Whisper-large-v3-turbo API
3. Groq processes the audio and returns transcribed text
4. The transcription is delivered back to your browser — Groq does not store the audio or transcript

Audio data is transmitted but never stored on any server. An internet connection is required.

AI Translation (Llama-3.3-70B via Groq)

1. Your subtitle text is sent to a Cloudflare Worker, which forwards it to Groq's Llama-3.3-70B API
2. Groq processes the text and returns the translation
3. The translation is delivered back to your browser — Groq does not store the text

Subtitle text is transmitted but never stored. An internet connection is required.

7. Changes to This Policy

We may update this privacy policy from time to time. Any changes will be reflected on this page with an updated date.

8. Contact

If you have questions about this privacy policy, please open an issue on our GitHub repository.