PDF Flatten Tool
Make a filled form or a commented PDF final. Flattening draws form field values, comments, stamps and drawings permanently into the page, so they look the same in every viewer, print correctly and can no longer be edited. Choose to flatten everything, only the elements that are printed, or only the form fields while keeping comments editable.
- Files stay on your device
- No sign-up
- Free to use
How to use PDF Flatten Tool
- Drop the PDF onto the page and check what was found.
- Choose what to flatten.
- Click “Flatten PDF”.
- Download the flattened file.
PDF Flatten Tool features
Forms and comments
Fields, notes, stamps, highlights and drawings.
Printable only
Keeps hidden-when-printing items interactive.
Forms only
Locks field values, leaves comments editable.
Appearance generation
Builds missing field appearances first.
Before/after counts
Shows what was flattened.
Private
Processing in your browser.
When to use PDF Flatten Tool
- Sending a completed form that must not be changed.
- Making stamps and signatures part of the page.
- Fixing forms that show empty fields in some viewers.
- Preparing reviewed documents for printing.
PDF Flatten Tool FAQ
What does flattening do?
It replaces interactive elements with their visual appearance drawn into the page content. The result looks the same but contains no fields or annotations.
Is flattening secure?
It prevents casual editing in PDF readers, not determined editing in PDF editors. Use a digital signature or Protect PDF for stronger guarantees.
Why do some fields look empty in other viewers?
Some programs store values without a visual appearance. The tool generates appearances before flattening so values are visible.
What does “printable only” mean?
Annotations marked not to print – for example reviewer notes – stay interactive and are not drawn into the page.
Can I undo flattening?
No. Keep the original file if you may need to edit it.
Is my PDF uploaded?
No. qpdf and pdf-lib run in your browser.
Flattening PDF forms and annotations
Interactive PDF elements – form fields, comments, stamps, highlights – live on a layer above the page content. Viewers draw them from separate appearance streams and let users change them. That is useful while a document is being filled or reviewed, but a finished document should usually look the same for everyone and not change.
Flattening merges each element’s appearance into the page content and removes the interactive object. qpdf does this for all annotation types. It first generates appearance streams for form fields that lack them, a common reason why a filled form shows empty boxes in browsers or on phones.
Three modes cover typical needs. Everything is right for a final copy. Printable only respects reviewers’ settings: notes marked “do not print” stay as interactive notes. Forms only uses pdf-lib to flatten just the form fields, so a filled form is locked while comments remain editable.
The before-and-after counts confirm what changed. Keep the original if you might need to edit the form again.
A common situation is a filled application form that looks complete on your computer but arrives with empty fields, because the recipient’s program ignores field values without appearances. Flattening before sending avoids that: the answers become ordinary page content that every viewer and printer shows.