PDF on iPhone: The Complete Guide

The iPhone is capable of handling almost every common PDF task natively, with no app downloads required for most of them. The challenge is knowing where the relevant features live — they're spread across the Files app, the Markup tool, Safari, and the Share menu rather than gathered in one place. This guide maps the full picture.

Viewing PDFs on iPhone

iOS opens PDFs automatically in a built-in viewer whenever you tap one — in Mail, Messages, Files, or Safari. The default viewer supports:

• Pinch-to-zoom and tap-to-fit navigation
• Page thumbnail scrubber for jumping through long documents
• Search within the document (tap the magnifying glass icon)
• Table of contents navigation if the PDF includes one

For PDFs saved in the Files app, tap the file to open it. The viewer is built into Files and handles most viewing tasks well. If you need more control — continuous scroll mode, night mode, or custom page layouts — Adobe Acrobat Reader (free) and UPDF both offer enhanced viewing experiences as free apps.

Saving PDFs on iPhone

PDFs on iPhone are stored in the Files app, either in iCloud Drive or On My iPhone storage. The standard method from any context is: tap the Share icon → Save to Files → choose a folder → tap Save.

For the full breakdown of every source (Safari, Mail, Messages, third-party apps) see our dedicated guide: How to Save a PDF on iPhone.

Scanning a Document to PDF on iPhone

iPhone has a document scanner built directly into the Notes app and the Files app — no third-party scanner needed.

• From Notes: New note → camera icon → Scan Documents
• From Files: Three-dot menu in any folder → Scan Documents

The scanner uses edge detection to crop the document automatically and saves the result as a multi-page PDF. For the complete workflow including quality tips, see How to Scan a Document to PDF on iPhone.

Annotating and Highlighting PDFs on iPhone

The Markup tool in the Files app provides a solid free annotation toolkit:

• Highlight text: long-press to select text → Highlight from the pop-up menu
• Add a text annotation: Markup toolbar → + → Text
• Freehand drawing: use the pen or pencil tools in the Markup toolbar
• Add a signature: Markup toolbar → + → Signature

Open any PDF in Files, tap the Markup icon (pencil in a circle) in the top right, and the annotation toolbar appears at the bottom. Tap Done to save.

For more annotation types — sticky notes, strikethrough, stamps — Adobe Acrobat Reader (free) adds these on top of what Markup provides. For a full comparison of iOS PDF annotation apps, see our Best PDF Apps for iPhone and iPad roundup.

Signing a PDF on iPhone

The Markup tool supports adding a stored signature to any PDF:

1. Open the PDF in Files and tap the Markup icon.
2. Tap + in the toolbar and select Signature.
3. Draw your signature with your finger (or Apple Pencil on iPad) and tap Done.
4. Position and resize the signature on the page.
5. Tap Done to save.

For documents with multiple signature fields, or where you need a more professional signing workflow, the eSign app (iOS) provides a purpose-built experience. See our eSign for iPhone review for a full breakdown of when it makes sense to use a dedicated signing app versus the built-in Markup tool.

Converting PDFs on iPhone

iOS doesn't have native PDF conversion built in, but your iPhone's Safari browser can access all of PDFToolShack's free conversion tools without any app download:

Compressing a PDF on iPhone

Scanned PDFs and photo-heavy documents can be large — too large for email attachments or messaging apps. You have two options:

• Browser-based: Open Safari on your iPhone, go to PDFToolShack's Compress PDF tool, upload your PDF, and download the compressed version. Works entirely in Safari, no app needed.
• App-based: UPDF for iOS includes compression as part of its free tier. Open the PDF in UPDF and use the compress function from the file options menu.

For a full comparison of compression methods and what each level does to file size and image quality, see our PDF compression guide.

Merging and Splitting PDFs on iPhone

The Files app doesn't have built-in merge or split functionality, but PDFToolShack's browser tools handle both directly in Safari:

• Merge PDF — combine multiple PDFs into one file
• Split PDF — divide a PDF by page range or split into individual pages

Open either tool in Safari on your iPhone, upload your files, and download the result. Both tools process files locally in your browser — no upload to external servers.

Making a Scanned PDF Searchable on iPhone

Scanned PDFs are image files — you can't select or search the text. To make a scanned PDF searchable on iPhone, open Safari and run it through PDFToolShack's PDF OCR tool. The tool adds a real text layer to the scanned pages, making the resulting PDF searchable in Files and any other PDF viewer.

Protecting a PDF with a Password on iPhone

To password-protect a PDF from your iPhone, open Safari and use the Protect PDF tool. The tool runs entirely in your browser — the file is encrypted locally using AES-256 and never uploaded to a server. Download the protected PDF and save it to Files.

What You Can't Do Natively on iPhone

For completeness: a few PDF tasks have no free built-in path on iOS and require either a browser tool or a paid app:

• Edit body text in a PDF — changing the words in an existing paragraph requires a desktop PDF editor like UPDF or Adobe Acrobat Pro. No free browser tool handles this reliably.
• Create fillable form fields — adding interactive form fields to a PDF is a desktop task.
• True redaction — permanently removing text data (not just covering it visually) requires a dedicated redaction tool.