Independent, structured comparison of four PDF platforms for everyday and professional use.
Not every PDF task requires enterprise software, and not every lightweight tool is suitable for professional work. This resource compares Sejda, PDF Buddy, Apple Preview, and Kdan PDF — four platforms addressing different ends of the PDF editing spectrum. The goal is to give you a factual picture of what each tool handles well, where it falls short, and which use cases it genuinely serves. No sponsored placements, no affiliate links — just structured information to help you evaluate options on your own terms.
These four platforms cover a practical range — from web-based simplicity to platform-native depth. Understanding where each sits helps narrow selection without extensive hands-on testing.
A web and desktop PDF editor covering a broad range of tasks including editing, merging, splitting, OCR, and form handling. Available via browser or desktop application, with processing limits on the web tier.
A straightforward browser-based editor aimed at users who need annotation, form filling, signature addition, and basic text insertion without installing software. Lightweight and accessible.
macOS and iOS built-in viewer and light editor. Handles annotations, signatures, form filling, and basic image manipulation natively. No installation required on Apple platforms — but limited to Apple ecosystems.
A cross-platform PDF suite with mobile-first design, covering reading, annotation, form filling, signing, and conversion across iOS, Android, Windows, and macOS. Offers cloud sync capabilities.
We evaluate each platform across key criteria relevant to individual and small team workflows. See the features page for detailed breakdowns.
How much can each tool actually edit? We distinguish between annotation-level changes, text insertion, and genuine text-layer editing — they are meaningfully different capabilities.
Web, desktop, or mobile — availability shapes whether a tool fits your environment. Apple Preview is macOS and iOS only. PDF Buddy is browser-only. Sejda and Kdan PDF span multiple platforms.
Password protection, encryption, and redaction support vary considerably. We document which platforms offer genuine protection versus superficial locks.
Each tool has an audience it serves reliably. Understanding the intended use case prevents mismatched expectations when evaluating what's documented versus what's practical.
Key criteria at a glance. Full 14-row comparison available on the comparison page.
| Criteria | Sejda | PDF Buddy | Apple Preview | Kdan PDF |
|---|---|---|---|---|
| Web access | ✓ | ✓ | ✗ | Limited |
| Desktop app | ✓ | ✗ | ✓ (macOS) | ✓ |
| Mobile | Limited | ✗ | ✓ (iOS) | ✓ |
| Text editing | ✓ | Basic | ✗ | Basic |
| OCR | ✓ | ✗ | ✗ | Limited |
| Encryption | ✓ | Basic | ✓ | ✓ |
| Digital signature | ✓ | ✓ | ✓ | ✓ |
| Linux | ✓ | ✗ | ✗ | ✗ |
✓ Supported | ✗ Not supported | Yellow = partial/limited. Data sourced from publicly available documentation. Verify with vendors for your version.