PDF Duo › Quick Look

PDF Duo or Quick Look on iPhone Duo?

iOS already shows a PDF as two pages on the open iPhone Duo with Quick Look, with Markup for quick notes. PDF Duo builds on that for reading and paperwork: a page curl over the spine, saved signatures, form filling field by field, your place remembered in every document, a laptop pose for signing and a flattened copy to send.

Updated 27 October 2026

Quick Look has

  • Two pages on the open Duo
  • Markup

PDF Duo adds

  • A page curl over the spine
  • Saved signatures, kept on this phone
  • Form filling field by field, with Next field
  • Your place remembered in every document
  • A laptop pose for signing
  • A flattened copy to send
  • The buttons in the Duo’s control column when closed

When Quick Look is enough

To glance at a PDF someone sent you, or scribble a quick note on it, Quick Look is already there, with nothing to install.

When PDF Duo is worth it

For long documents you come back to: the page curl, your place remembered, the PDF’s own contents, bookmarks and search with every match listed.

For paperwork: signatures you saved once, forms filled field by field, and a flattened copy that can’t be changed.

Open PDFs in PDF Duo

From Files, Mail, Safari or Messages, choose Open in PDF Duo. Or connect iCloud Drive or any folder once, and every PDF there is in the Library.

Questions

Do I need PDF Duo if I only read a PDF now and then?

Not necessarily. Quick Look shows two pages on the open Duo and has Markup. PDF Duo is for long reading and for signing and filling.

Does PDF Duo replace Markup?

It covers what Markup does (pen, highlight, text) and adds underline and strike-through by dragging across text, sticky notes, shapes, a list of every mark, and undo for every change.

Is PDF Duo free?

Yes. Reading, mark-up, form filling, signing and flattened export are all free, with no ads, no watermark, no account and no subscription.

Download on the App Store

Free on the App Store. Free · No ads · No watermark · No account