Legal

Privacy Policy

Last updated: March 2026

Short version: SubFlow runs entirely in your browser. We operate a minimal backend service solely to facilitate the OAuth authorization process — it handles a one-time authorization code and immediately discards it. We never see, store, or transmit your YouTube credentials or personal data.

1. Who We Are

SubFlow is a Chrome browser extension that helps YouTube creators translate video titles and upload multilingual subtitles. It is developed and maintained by an independent developer. For any questions, contact us at cherish.mxb@gmail.com.

2. Data We Collect

SubFlow does not collect, transmit, or store any personal data on external servers. The following information is stored locally in your browser only (via chrome.storage.local):

Your YouTube channel name and channel ID (to display in the extension UI)
Your Google OAuth access token and refresh token (to authenticate YouTube API requests and renew access silently)
Your Google account email address (used only to identify which account to silently refresh)

This data never leaves your device and is never accessible to us.

3. How We Use YouTube API

SubFlow uses the YouTube Data API v3 to perform the following actions on your behalf and only on your own channel:

Read your video's title, description, and existing subtitles
Update your video's localized titles
Download auto-translated subtitle files from YouTube
Upload subtitle tracks to your video

SubFlow's use of YouTube API Services is subject to the YouTube API Services Terms of Service. By using SubFlow, you also agree to Google's Privacy Policy.

4. Translation Requests

To translate video titles, SubFlow sends the title text to Google Translate's public endpoint. Only the video title text is transmitted — no personal information, credentials, or account details are included in these requests.

5. Backend Service

SubFlow operates a lightweight backend service (Cloudflare Workers) solely to facilitate the OAuth 2.0 authorization process. When you add a YouTube channel, your browser sends a one-time authorization code to this service, which exchanges it for access tokens using our OAuth credentials. The authorization code is single-use and is discarded immediately after the exchange. No personal data, account credentials, or video content is stored on this service.

6. Data We Do Not Collect

We do not store any data in databases
We do not use analytics or tracking tools
We do not share any data with third parties
We do not collect payment information

7. Revoking Access

You can revoke SubFlow's access to your YouTube account at any time by visiting the Google security settings page and removing SubFlow from the list of connected apps.

To delete locally stored data, uninstall the SubFlow extension from Chrome. All data stored in chrome.storage.local is automatically deleted upon uninstall.

8. Children's Privacy

SubFlow is not directed at children under the age of 13 and does not knowingly collect any information from children.

9. Changes to This Policy

We may update this Privacy Policy from time to time. The "Last updated" date at the top of this page will reflect any changes. Continued use of SubFlow after changes are posted constitutes your acceptance of the revised policy.

10. Contact

If you have any questions or concerns about this Privacy Policy, please contact us at:
cherish.mxb@gmail.com