iPhone Files app PDF tips: preview, mark up, combine, rotate and sign

Updated 13 October 2026 · ChatPDF guides · 13 sources

AI can miss or misstate things. Summaries and answers from AI tools, ChatPDF included, can leave out important details or get them wrong. Check anything that matters against the document itself, especially legal, medical, financial and exam material.

Key points
  • The Files app finds a PDF by its file name, folder name or document type, and can open it in Quick Look or another app with Open With. 1
  • From iOS 26, the built-in Preview app can search text, rotate, reorder, delete and insert pages, crop, highlight, fill in forms and sign PDFs. 2,3,4
  • To combine PDFs, open one in Preview and use Insert from File on a page thumbnail to add another PDF or image. 3
  • Preview can lock a PDF with a password and export a smaller copy; keep an unlocked duplicate if you might need one. 5,6

Your iPhone already has most of the PDF tools people go looking for in the App Store. The Files app stores and finds your documents, and since iOS 26 the Preview app opens, edits, signs and exports PDFs 7. This guide collects the most useful everyday tasks, with steps as Apple describes them in the iPhone User Guide.

Find a PDF quickly

  1. Open the Files app and type in the search field. Apple says you can search by file name, folder name or document type 1.
  2. To narrow the search, tap Recents or the name of a location or tag below the search field.
  3. Tap Recents to see files you opened recently, or Browse to look through iCloud Drive and other locations.

Files search works on names, not on the words inside a PDF. To find a word inside a document, open it and use Preview's search, described in how to search for text in a PDF on iPhone.

Two organizing habits pay off later. Touch and hold a file or folder and choose Tags to color-code it, or touch and hold a folder and choose Favorite so it appears on the Browse screen 8. Give scans and downloads meaningful names with Rename; a name like "Lease 2026 signed" beats "Scan 14".

Preview a PDF with Quick Look or open it in another app

Touch and hold the file, tap Open With, then choose Preview with Quick Look for a fast look, or another app on the list. To make one app the default for a file, touch and hold it, choose Get Info, and pick an app under Always Open With 1.

The Preview app has its own Recents, Shared and Browse tabs, so you can open documents without going through Files first. Inside a PDF you can show page thumbnails by tapping the page count, and jump to a page with Go to Page 2.

Rotate, reorder, delete or crop pages

All of these happen in Preview 3:

If you change your mind, the More menu has Undo. A PDF you keep in a note can also be rotated page by page from the Notes app 9.

Combine several PDFs into one

  1. Open the first PDF in Preview and tap the page count to show thumbnails.
  2. Touch and hold the thumbnail of the page that the new material should follow.
  3. Tap Insert from File and choose another PDF or an image. You can also tap Scan Pages to add paper pages straight from the camera 3.
  4. Drag thumbnails to fix the order, then save.

If you want to keep the originals untouched, make a copy first with Duplicate from the menu next to the file name 5.

Highlight, annotate, fill in and sign

Lock or shrink a PDF

To protect a document, open it in Preview, tap the arrow next to the file name, tap Lock and enter the same password twice. Apple suggests making a Duplicate first if you also want a copy without a password 5. To send a smaller file, use Export from the same menu; for PDFs on iOS 27 there are options such as Optimize Images for Screen, which lowers image resolution 6.

Where ChatPDF helps

Files and Preview handle the file itself. When the problem is the content, for example a long report you need to understand, an AI tool can help you ask questions about it. ChatPDF imports a PDF from inside the app through the standard document picker, so anything you can see in Files (iCloud Drive, On My iPhone and storage services that appear in Files) can be added. ChatPDF is not a PDF viewer or editor and does not annotate, rotate or merge files, so do your page work in Preview first. See getting started with ChatPDF and which PDFs work.

Common questions

Do I need iOS 26 to use Preview on iPhone?

Yes. The Preview app is part of iOS 26 and later. On older versions you can still find files and open them in Quick Look from the Files app. 7,1

Can I combine PDFs without a third-party app?

Yes. Open the first PDF in Preview, touch and hold a page thumbnail, tap Insert from File and pick the next PDF or an image. 3

Why can I not select text in my PDF?

The PDF is probably a scan, which is a picture of the page without a text layer. You need OCR to add one; see the guide on scanned PDFs. 13

Sources and further reading

  1. Apple Support. Find and view files and folders in Files on iPhone (iPhone User Guide). support.apple.com
  2. Apple Support. Open and view PDFs and images in Preview on iPhone (iPhone User Guide). support.apple.com
  3. Apple Support. Add, delete, rotate, move, or crop PDF pages in Preview on iPhone (iPhone User Guide). support.apple.com
  4. Apple Support. Annotate a PDF or image in Preview on iPhone (iPhone User Guide). support.apple.com
  5. Apple Support. Lock PDFs in Preview on iPhone (iPhone User Guide). support.apple.com
  6. Apple Support. Export or compress PDFs and images in Preview on iPhone (iPhone User Guide, iOS 27). support.apple.com
  7. Apple Support. Get started with Preview on iPhone (iPhone User Guide). support.apple.com
  8. Apple Support. Organize files and folders in Files on iPhone (iPhone User Guide). support.apple.com
  9. Apple Support. Work with PDFs in Notes on iPhone (iPhone User Guide). support.apple.com
  10. Apple Support. Draw and handwrite with Markup on iPhone (iPhone User Guide). support.apple.com
  11. Apple Support. Fill out and sign PDF forms in Preview on iPhone (iPhone User Guide). support.apple.com
  12. Apple Support. Fill out forms, sign documents, and create signatures on iPhone (iPhone User Guide). support.apple.com
  13. OCRmyPDF documentation. Introduction. ocrmypdf.readthedocs.io
Ask your own PDFs with ChatPDF

Import a PDF from the Files app, then ask questions, get a summary or key takeaways, or make a quiz or flashcards from it. Requires a subscription; check the app for current plans.

Download on the App Store

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