PDF Duo › Flatten

How to flatten a PDF on iPhone

In PDF Duo, choose More › Export flattened and your signature, marks and form values are burned into the page, so the person you send it to can’t move or lift them. It’s free, with no watermark, and your original stays as it was.

Updated 27 October 2026

What flattening does

A PDF keeps annotations, form values and placed signatures as separate objects on top of the page, and anyone with a PDF editor can move, change or delete them. Flattening makes them part of the page itself.

Flatten a PDF in PDF Duo

  1. Open the signed or filled PDF in PDF Duo.
  2. Tap More, then Export flattened.
  3. Send or save the copy. It is named “(flattened)”; your original keeps its marks editable.

Without an app: the Print trick

iOS has no flatten button. The usual workaround is to print the PDF to a new PDF: tap Share › Print, then share the preview from the Print options and save it to Files. The steps vary between iOS versions, and you lose the form fields along the way. It works when you can’t install anything.

Flattened is not certified

Flattening fixes your marks to the page; it is not a certificate-based digital signature, and it doesn’t prove who signed.

Questions

Does flattening change my original PDF?

No. Export flattened makes a copy named “(flattened)”. The original keeps its marks and form fields editable.

What gets flattened?

Your signature, every mark (highlights, pen, text boxes, notes, shapes) and the form values.

Is flattening free?

Yes, with no watermark, no account and no subscription.

Can a flattened PDF still be edited?

The marks can’t be moved or lifted, because they are part of the page. Someone with a full PDF editor can still draw over it or edit the page.

Download on the App Store

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