App Comparison
Adobe has name recognition. But their signing app is 470MB, collects your data, and doesn't support Apple Pencil. Here's why smaller is better.
| Feature | eSign PDF | Adobe Fill & Sign |
|---|---|---|
| App size | Under 50 MB | 470+ MB |
| Apple Pencil support | Full support with palm rejection and pen styles | No dedicated Apple Pencil support |
| Data collection | Zero data collected, 100% on-device | Collects usage data, documents stored in Adobe Cloud |
| Account required | No | Adobe ID required for full features |
| Signature pen styles | Fountain, Ballpoint, Monoline, Marker | Basic drawing only |
| AI field detection | Yes, auto-detects signature and date fields | Basic form field recognition |
| Works offline | Yes, fully offline | Limited offline functionality |
| Tamper-proof export | Yes, PDF flattening included | Available in Acrobat Pro only |
| Camera scanning | Built-in with auto-crop | Available via Adobe Scan (separate app) |
| Stamps (Approved/Draft) | Yes, built-in | Not available |
Adobe Fill & Sign is best for
Adobe Fill & Sign is best for people already in the Adobe ecosystem who want integration with Acrobat Pro, Document Cloud, and Creative Cloud. If you use Acrobat on desktop and want mobile continuity, Adobe makes sense. Also good if you need free basic signing without a subscription.
Adobe Fill & Sign is part of the Adobe Acrobat ecosystem. It lets you fill PDF forms and add signatures on mobile devices. It's backed by Adobe's PDF expertise and integrates with Adobe Document Cloud. The app is free to download but pushes users toward Acrobat Pro subscriptions for advanced features. At 470MB, it's one of the largest signing apps on the App Store.
Pricing: Free basic features. Acrobat Pro: $19.99/month ($239.88/year) for advanced features.
eSign PDF is best for
eSign PDF is best for anyone who wants a fast, lightweight, private signing app. Under 50MB, full Apple Pencil support, 4 pen styles, form filling, AI field detection, and tamper-proof export. No account, no data collection, no internet required.
Pricing: $4.99/week, $29.99/year, or $59.99 lifetime
eSign PDF is under 50MB. Adobe Fill & Sign is 470MB+. On a 64GB iPhone, that difference matters. eSign PDF launches faster, uses less memory, and doesn't slow down your phone. Adobe's bloat comes from bundling their entire PDF rendering engine and pushing you toward the broader Acrobat ecosystem.
This is a surprising gap. Adobe, one of the biggest creative software companies, doesn't offer dedicated Apple Pencil support in their signing app. eSign PDF has full Apple Pencil integration with palm rejection and four distinct pen styles. If you sign on an iPad with Apple Pencil, eSign PDF produces significantly better-looking signatures.
Adobe collects usage data and encourages Document Cloud storage. eSign PDF collects zero data and processes everything on-device. For signing NDAs, medical forms, financial documents, and personal contracts, the privacy difference is meaningful. Your documents literally never leave your phone with eSign PDF.
Choose Adobe Fill & Sign if you're already paying for Acrobat Pro and want integration with your existing Adobe workflow. The free tier is decent for basic signing. Choose eSign PDF if you want a fast, lightweight, private signing app with better signature tools. It's 10x smaller than Adobe, has Apple Pencil support Adobe lacks, and your documents stay completely on your device. For most iPhone users, eSign PDF is the better choice.