rExif / docs / metadata-scrubbing

Metadata Scrubbing and Privacy

Sanitizing sensitive GPS coordinates, device serial numbers, and embedded thumbnails for safe public sharing.

Why Metadata Scrubbing Matters

Photographs captured using modern smartphones and camera bodies embed a considerable amount of background telemetry:

  • Pinpoint Geographic Data: GPS latitude, longitude, altitude, and heading angle.
  • Hardware Serial Numbers: Unique identifier tokens for the camera body, lens, and internal sensor.
  • User and Environment Telemetry: Computer user account names, editing software history, and embedded thumbnail images which might reveal uncropped versions of a redacted photo.

Sharing unscrubbed files on public web forums, classified ads, or messaging channels exposes personal routines and home addresses to automated scrapers.

Sanitization Profiles in rExif

rExif provides granular scrubbing options to balance technical utility with privacy needs:

1. Remove GPS Only

Retains all technical exposure parameters (exposure time, f-stop, ISO, color profile) while stripping every geographic reference:

  • Clears GPSLatitude, GPSLongitude, GPSAltitude, GPSTimeStamp, and GPSImgDirection.
  • Removes reverse-geocoded IPTC city, state, postal code, and country records.

2. Remove Hardware and Personal Telemetry

Removes data identifying specific individuals or hardware serial numbers:

  • Camera body and optical lens serial numbers.
  • Owner name, artist attribution, and free-form user comments.
  • Manufacturer proprietary MakerNotes (Apple, Canon, Nikon, Sony).

3. Full Sanitization (Strip All Metadata)

Removes all EXIF, IPTC, and XMP structures alongside embedded thumbnail caches:

  • Retains only the foundational headers necessary for image rendering (dimensions, sRGB/Display P3 color space, and DPI density).
  • Often reduces total file weight by 15% to 25%, expediting web delivery.

Exporting Sanitized Copies

To safeguard primary raw assets, rExif supports creating clean derivative copies:

  1. Select the images intended for distribution.
  2. Click Export Sanitized Copies….
  3. Choose a destination folder (e.g. Sharing/) or append an automated suffix like _clean.jpg.
  4. Your master library files remain completely intact with full metadata, while exported copies are stripped and safe for public release.

[!IMPORTANT] Unlike web-based metadata stripping tools that require uploading your photos to third-party cloud servers, rExif executes all processing within local Mac memory, ensuring total confidentiality.