Silo PDF: Private PDF Tools

PDF tools that stay on your phone. Pay once. Use forever.

Silo is a private, on-device PDF toolkit for iPhone and iPad. Open a document, edit it, save the result. Nothing is ever uploaded. No account. No subscription. No tracking. Just a fast, focused PDF app that respects what's inside your files.

EVERYTHING RUNS ON YOUR DEVICE

Open a packet sniffer next to any other PDF tool and watch what happens when you compress a document: your file is uploaded to a server, often in another country. Open one next to Silo and watch nothing happen. Compress, OCR, redact, scan, watermark — every operation runs locally using Apple's own frameworks. Your contracts, tax returns, medical records and client documents never leave your iPhone.

ONE PAYMENT. NEVER AGAIN.

Most serious PDF apps on iOS are now yearly subscriptions. Silo is a one-time purchase. You pay once and the app is yours — no recurring fee, no expiring license, no surprise "Pro+" tier next year, no upsell screen tucked behind every button. The price you pay is the price.

FREE FOREVER

• Beautiful PDF viewer with smooth scroll and pinch-zoom
• Set Silo as your default PDF viewer on iOS 26
• Recents, search, and Files app integration
• Merge multiple PDFs in any order
• Split a PDF by range, by count, or by specific pages
• Rotate pages, individually or all at once
• Convert images to a single PDF

PRO TOOLS — UNLOCK ONCE

• Document scanner — Apple's edge-detection camera, multi-page output
• Compress for email or web with target-size presets
• OCR — make scanned PDFs searchable, powered by Apple Vision
• Redact — find and remove SSNs, EINs, phone numbers, emails and dates
• Reorder and delete pages with drag-to-reorder thumbnails
• Password protect with user and owner passwords
• Watermark with custom text, opacity, rotation and tiling
• Extract selected pages into a new PDF

BUILT ON APPLE FRAMEWORKS

Silo uses Apple's PdfKit for rendering, the Vision framework for OCR, and VisionKit for the document scanner. There are no third-party PDF servers, no cloud-OCR APIs, no analytics SDKs and no crash reporters that read your file contents. The only network calls Silo makes are to Apple and to RevenueCat to verify your purchase. Both are listed in Settings → Privacy.

WHAT SILO WILL NEVER DO

Silo has a privacy nutrition label of "Data Not Collected" in the App Store