Privacy Policy

Last updated: April 15, 2026

1. Information We Collect

CapnAI collects minimal information to provide our service:

• Photos: Images you select or capture are transmitted to third-party AI services for caption generation. Photos are processed in real-time and are not stored on our servers or by our AI providers.
• Optional Profile Data: If you choose to provide your gender and age range during onboarding, this information is included with AI requests solely to generate more personalized captions. This data is optional and never required.
• Brand Voice Samples (Pro): If you use the Brand Voice feature, sample captions you enter are sent to AI services to match your writing style. These are not stored beyond the current session.
• Device ID: A unique device identifier is used for rate limiting and anonymous usage tracking. It is not linked to your personal identity.
• Usage Data: We collect anonymous metrics such as generation count, platform preferences, and feature usage to improve the app.
• Purchase Data: Subscription status is managed by RevenueCat and Apple/Google. We do not store payment information.

2. How We Use Your Information

• Generate AI-powered captions based on your photos and preferences
• Personalize captions using optional profile data (age range, gender) — only if provided
• Enforce daily usage limits and prevent abuse
• Improve caption quality and overall app experience
• Process in-app purchases via Apple/Google

3. Third-Party Services That Receive Your Data

When you generate captions, your photo and any optional profile data are sent to the following AI services for processing:

• Google Gemini AI (primary): Receives your photo and optional profile data to analyze the image and generate captions. Governed by Google's Privacy Policy.
• OpenAI (fallback): Used as a backup if Google Gemini is unavailable. Receives the same data under the same conditions. Governed by OpenAI's Privacy Policy.

We also use the following services for app infrastructure:

• Supabase: Hosts our serverless functions that proxy requests to AI providers and store anonymous usage counters.
• RevenueCat: Manages subscription status and purchase verification.
• Google AdMob: Displays ads to free-tier users. AdMob may collect device advertising identifiers per Google's ad policies.
• Sentry: Collects anonymous crash reports and error logs to help us fix bugs.

4. Third-Party Data Protection

All third-party services we use are bound by their own privacy policies and data protection commitments. Google, OpenAI, Supabase, RevenueCat, and Google AdMob each maintain data security standards that meet or exceed industry requirements. Neither Google nor OpenAI uses data submitted via API for training their models under their current API terms of service.

5. Data Storage

Caption history and app preferences are stored locally on your device only. Server-side, we store only anonymous usage counters (device ID + daily generation count). Photos, profile data, and brand voice samples are never stored on our servers.

6. Data Sharing

We do not sell or trade your personal information. We share data with third parties only to the extent necessary to operate the service, as described in Section 3 above. Specifically:

• Photos are shared with Google Gemini AI and, when needed, OpenAI — for caption generation only.
• Optional profile data (age range, gender) is shared with the same AI providers to personalize results.
• No other personal data is shared with advertising networks or data brokers.

7. User Consent

Before using CapnAI's caption generation feature for the first time, users are presented with a clear disclosure explaining what data is sent, which third-party AI services receive it, and how it is used. Caption generation requires your explicit agreement to this disclosure.

8. Children's Privacy

CapnAI is not intended for children under 13. We do not knowingly collect information from children under 13.

9. Changes to This Policy

We may update this privacy policy from time to time. Changes will be posted on this page with an updated revision date.

10. Contact Us

If you have questions about this privacy policy, contact us at support@tuanhoang.dev.