Scope
This policy covers the SuTu app for iPhone and iPad and the website at sutu.caiths.com. It explains how the app uses photos you provide, on-device settings, and local processing history.
Photos and files
The Photos entry uses Apple's system picker, so the app receives only items you explicitly select. Files, clipboard, and iPad drag-and-drop imports are also processed only after a direct action from you.
Resizing, compression, enhancement, cropping, and format conversion use Apple system frameworks on your device.
System permissions
If you decline photo-library write access, you can still save to Files or send results through the system share sheet.
- Add Photos: used only to write copies you confirm to the system photo library.
- Clipboard: read only after you choose Paste from Clipboard.
- Files: accessed temporarily through the system document picker or drag session.
Data stored on device
Preferences, small history thumbnails, and preview cache stay inside the app sandbox. History does not contain original file paths or original photos. You can clear cache and history in the app; uninstalling removes this local data.
Exports and metadata
Exported copies are re-encoded in the selected format. GPS, camera, lens, serial-number, and other source metadata are removed by default. General sharing output is converted to SDR sRGB with orientation baked upright.
Collection and tracking
- No account, ads, analytics, or user profiling.
- No Firebase, Crashlytics, or third-party statistics SDKs.
- No cross-app or cross-site tracking.
- No cookies or browser local storage for website analytics.
Website infrastructure
The site is hosted by GitHub Pages, with Cloudflare used only for DNS. Infrastructure providers may keep ordinary security and operations logs such as IP address, time, and request path. SuTu does not connect those logs to photos in the app or operate a separate analytics service.
Children's privacy
SuTu is not designed to collect information from children. Because the app has no accounts, uploads, or personal-data collection, we do not knowingly collect children's personal information.
Changes to this policy
If features, data practices, or applicable rules materially change, we will update this policy and place the new effective date at the top of the page.
Contact
Contact the developer with questions about this policy or SuTu's data practices.