The Privacy Risk of Web-Based Converters

Searching for "convert image to PDF" typically leads to ad-heavy websites that ask you to upload your pictures to a remote server. When your photos contain sensitive personal details — such as government IDs, tax slips, medical receipts, or utility bills — uploading them introduces serious privacy and data retention risks.

Fortunately, your iPhone has plenty of processing power to render high-resolution PDFs directly on the device.

Method 1: Using the Native Photos App (The Print Trick)

Apple includes a hidden way to create a PDF from the Photos app using the system Print preview:

  1. Open the Photos app on your iPhone.
  2. Tap Select in the top-right corner and choose the photos you want in your PDF.
  3. Tap the Share button (box with an upward arrow) in the bottom-left corner.
  4. Scroll down the share sheet and tap Print.
  5. On the Print Options screen, locate the thumbnail preview at the bottom. Pinch outward with two fingers on the preview (as if zooming in on a photo).
  6. The preview expands into a generated PDF. Tap the Share button at the top right to save it to the Files app or send via Mail.

Limitations of the Print Trick: You cannot easily reorder pages before printing, you cannot crop or rotate individual photos, you cannot adjust margin sizing, and the resulting file size can be massive (often 30–50 MB for just a few photos) because it saves at uncompressed printer resolution.

Method 2: Using img2pdf (Fast, Structured & Compressed)

For complete control over page order, layout size, redaction, and file size, the free img2pdf app performs the entire conversion on-device in seconds:

  1. Open img2pdf on your iPhone.
  2. Tap Choose photos to select one or dozens of pictures from your library.
  3. Reorder pages: Simply drag and drop page thumbnails to arrange them in the exact order you need.
  4. Edit pages: Tap any page thumbnail to crop uneven margins, rotate sideways photos, or use the Redact tool to black out sensitive information.
  5. Select your preset: Choose Small (compact B&W for email), Standard (balanced colour for paper copies), or Best (full photo quality).
  6. Tap Save PDF. Your PDF is generated instantly and ready to share or save to Files.

Comparing the Two Approaches

Feature Apple Photos Print Trick img2pdf App
Privacy 100% On-Device 100% On-Device
Drag-and-Drop Reordering ❌ No ✅ Yes
Page Size Control (Letter / A4) Limited ✅ Letter, A4, Original
Redaction / Signature ❌ No ✅ Yes
File Size Optimization ❌ Huge files ✅ Small / Standard / Best presets
Password Protection ❌ No ✅ Yes

Tips for Best PDF Quality

  • Match the recipient's standard: Use US Letter for contacts in the United States and Canada; choose A4 for European and international organizations.
  • Check file size before emailing: Most email providers limit attachments to 20–25 MB. Using the Small or Standard preset ensures your PDF delivers without bouncing.
  • Use the iOS Share Extension: You can select photos in Apple Photos, tap Share, and choose img2pdf to begin converting immediately.