Strip all sensitive metadata from image files.

strip-metadata.sh

#!/usr/bin/env bash
#
# strip-metadata.sh — Strip all sensitive metadata from image files.
#
# Images can contain hidden metadata that leaks private information:
#   - EXIF: camera model, serial number, software version, timestamps
#   - GPS: exact latitude/longitude where the photo was taken
#   - ICC profiles: color profiles that can reveal the device or software used
#   - XMP/IPTC: author names, copyright info, editing history
#
# This script uses exiftool to remove ALL of the above in one pass.
#
# Usage:
#   ./strip-metadata.sh [options] <image> [image2 ...]
#
# Options:
#   -n, --dry-run   Show metadata without removing
#   -y, --yes       Skip confirmation prompt
#   -h, --help      Show this help message
#
# Examples:
#   ./strip-metadata.sh photo.jpg                Single file
#   ./strip-metadata.sh *.jpg *.png              Batch process
#   ./strip-metadata.sh -n photo.jpg             Preview what would be removed
#   ./strip-metadata.sh -y *.jpg                 Strip without confirmation

set -o errexit
set -o nounset
set -o pipefail

usage() {
  sed -n '/^# Usage:/,/^[^#]/{/^#/s/^# \{0,1\}//p;}' "$0"
  exit "${1:-0}"
}

# Require exiftool — the standard tool for reading/writing image metadata
if ! command -v exiftool &>/dev/null; then
  echo "Error: exiftool is required." >&2
  echo "  macOS:  brew install exiftool" >&2
  echo "  Debian: apt install libimage-exiftool-perl" >&2
  echo "  Fedora: dnf install perl-Image-ExifTool" >&2
  exit 1
fi
echo "Using: $(command -v exiftool)"
echo

DRY_RUN=false
SKIP_CONFIRM=false

while [[ $# -gt 0 ]]; do
  case "$1" in
    -n|--dry-run) DRY_RUN=true; shift ;;
    -y|--yes)     SKIP_CONFIRM=true; shift ;;
    -h|--help)    usage 0 ;;
    --)           shift; break ;;
    -*)           echo "Unknown option: $1" >&2; usage 1 ;;
    *)            break ;;
  esac
done

if [[ $# -eq 0 ]]; then
  echo "Error: no files specified." >&2
  usage 1
fi

# Warn before destructive operation
if ! $DRY_RUN && ! $SKIP_CONFIRM; then
  echo "This will permanently strip metadata from $# file(s) in place."
  read -rp "Continue? [y/N] " answer
  [[ "$answer" =~ ^[Yy]$ ]] || { echo "Aborted."; exit 0; }
fi

processed=0
skipped=0

for file in "$@"; do
  if [[ -L "$file" ]]; then
    echo "Skipping: $file (symlink)" >&2
    skipped=$((skipped + 1))
    continue
  fi

  if [[ ! -f "$file" ]]; then
    echo "Skipping: $file (not found)" >&2
    skipped=$((skipped + 1))
    continue
  fi

  mime=$(file --brief --mime-type "$file")
  if [[ "$mime" != image/* ]]; then
    echo "Skipping: $file (not an image: $mime)" >&2
    skipped=$((skipped + 1))
    continue
  fi

  echo "=== $file ==="

  if $DRY_RUN; then
    # -G1: show metadata group names (e.g. [EXIF], [GPS], [ICC_Profile])
    #       so you can see exactly where each tag comes from
    exiftool -G1 "$file"
    echo
    processed=$((processed + 1))
    continue
  fi

  # -all=             Remove all metadata tags (EXIF, XMP, IPTC, GPS, etc.)
  # -icc_profile:all= Also remove ICC color profiles (not covered by -all=)
  # -overwrite_original  Modify the file in place without creating a backup
  if ! exiftool -all= -icc_profile:all= -overwrite_original "$file"; then
    echo "Warning: could not strip metadata from $file" >&2
    skipped=$((skipped + 1))
    echo
    continue
  fi

  # Verify: count remaining tags, excluding ExifTool/System/File groups
  # which are structural (image dimensions, encoding) and can't be removed
  remaining=$(exiftool -G1 -s "$file" | grep -cv '^\[ExifTool\]\|^\[System\]\|^\[File\]' || true)
  echo "Done. Remaining non-structural tags: $remaining"
  echo
  processed=$((processed + 1))
done

echo "---"
if $DRY_RUN; then
  echo "Previewed: $processed | Skipped: $skipped"
else
  echo "Stripped: $processed | Skipped: $skipped"
fi

if [[ $processed -eq 0 ]]; then
  exit 1
fi