Flatten a PDF
Flatten a PDF so filled-in form answers and annotations become a fixed part of the page. After that they can’t be edited in a normal PDF reader, and the document looks the same in every app.
or drop a file here
One PDF, up to 250 MB.
Processed on your device. Nothing is uploaded.
How to flatten a PDF
Open the PDF
Usually a completed form, or a document with comments on it.
Choose what to flatten
Form fields, annotations, or both.
Flatten and download
You’re told how many fields and annotations were merged into the page.
What flattening covers
Form answers
Typed answers and ticked boxes turn into ordinary page content. Dropdown choices too.
Markup and stamps
Highlights and stamps are merged into the page, along with any ink drawings. Links still click.
Same look everywhere
Some apps show form fields slightly differently. A flattened page looks identical in Preview or Acrobat, and on paper.
When to flatten (and what it isn’t)
Flatten a form once you’ve finished it and before you send it, especially if it’ll be printed or filed, or forwarded to someone who shouldn’t change your answers. It’s also a sensible last step after signing or adding text.
Flattening isn’t a lock. Someone with editing software can still change the page, as they could with any PDF. If you need to stop people opening it, add a password with Protect PDF.
Privacy and security
Forms often hold personal details: dates of birth, addresses, National Insurance numbers. Flattening happens in your browser, so those details aren’t uploaded.
Read more in our privacy policy.
Flatten PDF FAQs
Can I undo flattening?
Not on the flattened copy. Keep the original if you might need to edit the answers later.
What happens to comment pop-ups?
The visible markers stay on the page, but text that only lives inside a pop-up note isn’t printed onto it. Check nothing important is hidden in one.
It says nothing was flattened
The PDF has no fillable fields or visible annotations. Scans and printed-to-PDF files are usually like that already.