Quick summary: Use Apple Preview (iOS 26) for opening, viewing, signing, and quick finger markup on PDFs without downloading third-party software. Choose img2pdf (requires iOS 18 or later) when you need to capture camera scans with auto-edge detection, put both sides of an ID card on one page, visually reorder pages, or compress oversized files for email.
Overview: Apple Preview on iPhone vs img2pdf
Apple documents Preview on iPhone in Apple Support: Get started with Preview on iPhone and Apple Support: Export or compress PDFs and images in Preview on iPhone (both checked November 2026).
In iOS 26, Apple introduced a dedicated Preview app on iPhone, giving mobile users a native viewer for PDFs and images with markup, signing, document scanning, and basic export controls. It serves as a great default viewer.
However, when assembling multi-page document packages, scanning driver's licenses, organizing mixed camera roll photos, or complying with strict email and upload portal file size limits (such as 2MB limits on job portals), standalone utility software like img2pdf provides specialized workflows that Apple's built-in viewer does not offer.
Feature Comparison: Apple Preview (iOS 26) vs img2pdf
| Feature | Apple Preview (iOS 26) | img2pdf |
|---|---|---|
| Price & Availability | Free (Pre-installed in iOS 26) Source: apple.com, checked Nov 2026 |
Free ($0, no subscriptions or in-app purchases) Source: App Store ID 6762545311, checked Nov 2026 |
| iOS Version Required | iOS 26 or later | Requires iOS 18 or later |
| Document Camera Scanner | Built-in camera scanner (auto/manual shutter, crop, rotate, color filters) Source: apple.com, checked Nov 2026 |
Apple VisionKit scanner with auto-edge detection, color filters, and multi-page batch scanning |
| ID Card 2-Up Layout | ❌ No (scans each side as a separate full page; no 2-up dual-sided card mode) | ✅ Dedicated mode: puts both sides of an ID card on one PDF page |
| Page Reordering | Thumbnail strip: touch, hold, and drag thumbnail up or down Source: apple.com, checked Nov 2026 |
Full interactive visual grid; sort by photo date; reverse order |
| File Size Presets & Targets | Export toggles ('Optimize Images for Screen' & 'Save Images as JPEG'); no DPI presets or size estimates Source: apple.com, checked Nov 2026 |
Small (150 DPI B&W), Standard (200 DPI), Best (300 DPI) with live size estimates |
| Standardized Paper Sizes | Maintains source image proportions; no A4 or US Letter page margin layout | Standard US Letter and A4 page formats with margin adjustment |
| Redaction Tool | Markup tools (pen, highlighter, shapes); no dedicated redaction tool | Dedicated opaque redaction block tool for PII and IDs |
| Searchable PDF (On-Device OCR) | Export toggle 'Embed Text' runs on-device OCR to make PDF searchable Source: apple.com, checked Nov 2026 |
Apple Vision framework on-device OCR generates searchable text layer |
| On-Device Privacy | 100% on-device processing with optional iCloud Drive sync | 100% on-device processing (Data Not Collected) |
Where Apple Preview (iOS 26) Is Better
- Zero download required: Preview is pre-installed on iOS 26 devices out of the box.
- Quick viewing & markup: Fast document loading, sketch tools, and signature placement for reviewing signed agreements.
- System integration: Default handler for viewing PDFs received in Mail, Messages, and AirDrop.
Where img2pdf Is Better
- Put both sides of an ID card on one PDF page: img2pdf captures the front and back of a driver's license and formats both sides cleanly onto a single Letter or A4 sheet, which Apple Preview cannot do.
- Multi-image assembly: Combine photos from your library, newly scanned paper pages, and imported PDFs into one coherent document.
- Reliable email compression: Avoid email bounces and portal upload rejections by choosing the Small (under 2MB) preset with live size calculation before saving.
- Permanent redaction: Draw solid black privacy masks over sensitive financial numbers, tax IDs, or personal data before sharing.
- Wider device compatibility: Works on any device running iOS 18 or later, while Apple's Preview app requires iOS 26.
Verdict: When to Use Each Tool
Use Apple Preview if: You are on iOS 26 and simply need to open an existing PDF sent to you, sign a single page with your finger, or read through a digital manual.
Use img2pdf if: You need to scan paper documents, convert HEIC camera photos, combine the front and back of an ID card onto one page, rearrange page order, or shrink file sizes to pass strict 2MB job or visa portal limits.
Frequently Asked Questions
What is the Apple Preview app on iPhone in iOS 26?
In iOS 26, Apple introduced a dedicated Preview app for iPhone, adapting macOS Preview capabilities for mobile users. It provides native viewing, fast markup, digital signatures, and basic PDF export without third-party app installations.
Can Apple Preview put both sides of an ID card on one page?
No. Apple Preview on iPhone does not have a 2-up dual-sided card scanner mode. If you scan or open two card photos, they are displayed on two separate pages. img2pdf has a dedicated ID card mode that automatically aligns front and back scans onto one standard page.
Can Apple Preview compress a PDF to under 2MB for email?
Apple Preview on iPhone includes export toggles to 'Optimize Images for Screen' and 'Save Images as JPEG', but it does not provide fine-grained compression controls, target file size estimators, or black-and-white downsampling presets. img2pdf includes transparent Small (150 DPI B&W), Standard (200 DPI), and Best presets with live output size estimation.
Which app is more private?
Both apps process documents locally on your device. Apple Preview integrates with your Apple ID and optional iCloud Drive, while img2pdf has no account requirement, zero network calls, and Apple Privacy Nutrition Label classification of Data Not Collected.
The dedicated PDF compiler for iPhone
Scan documents, format ID cards, and compress PDFs on-device.
