Stripping Metadata from Photos for Privacy

Why and How to Strip Photo Metadata

Removing metadata from photos before sharing them online is one of the most effective privacy measures you can take. This guide covers the technical approaches and their trade-offs.

Canvas Re-rendering Method

The browser-based approach used by this tool works by drawing the image onto an HTML Canvas element and exporting it as a new file:

// Simplified metadata stripping via Canvas
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
canvas.width = img.naturalWidth;
canvas.height = img.naturalHeight;
ctx.drawImage(img, 0, 0);
canvas.toBlob(blob => {
  // blob contains the image without any metadata
}, 'image/jpeg', 0.95);

Advantages: Works entirely in the browser, no server needed, removes ALL metadata including MakerNote and thumbnails.

Limitations: JPEG re-encoding causes minor quality loss (mitigated by using quality 0.95), does not preserve ICC color profiles unless manually transferred.

What Gets Removed

A thorough metadata strip removes:

• EXIF data: All camera settings, dates, GPS, orientation
• IPTC data: Captions, keywords, copyright, creator info
• XMP data: Adobe metadata, editing history, sidecar data
• ICC profiles: Color space definitions (may affect color accuracy)
• Thumbnails: Embedded preview images
• MakerNote: Proprietary camera data including serial numbers
• Comments: JPEG COM markers

Orientation Caveat

When stripping EXIF data, the Orientation tag is also removed. Many images taken on phones are stored rotated with an EXIF orientation flag telling viewers how to display them. After stripping, the image may appear rotated incorrectly. The Canvas method handles this correctly because the browser applies orientation before drawing, but command-line tools may not.

Verification

After stripping metadata, always verify the result:

1. Load the stripped image back into a metadata viewer
2. Confirm that all EXIF tags return empty
3. Check that no GPS coordinates remain
4. Verify the thumbnail is gone or updated
5. Confirm image dimensions and quality are acceptable

Batch Processing Considerations

For removing metadata from many photos, command-line tools like ExifTool offer batch processing:

# Remove all metadata from all JPEGs in a directory
exiftool -all= *.jpg

# Remove GPS only, keep other EXIF
exiftool -gps:all= *.jpg

# Remove all metadata but preserve orientation
exiftool -all= -tagsfromfile @ -orientation *.jpg

For browser-based batch processing, each image must be loaded and re-rendered individually, which is slower but requires no software installation.