What happens when flattening?

Forms, annotations and comments become a permanent part of the document and can no longer be edited.

When should I flatten a PDF?

Flatten a PDF before sharing if you want to prevent editing of form fields or comments.

How do I make a filled PDF form non-editable?

Upload the filled form and click Flatten. The field contents become ordinary page content, so recipients see the answers but cannot change them — useful before submission or archiving.

What does flattening a PDF mean?

Flattening merges the interactive layers — form fields, annotations and comments — into the page itself, so the document consists of fixed content only. The appearance is preserved, but the elements can no longer be edited.

Does flattening remove my comments?

No, they do not disappear — they become permanent. Comments and highlights are drawn into the page, so they remain visible but can no longer be moved, edited or deleted.

Is it free to flatten a PDF?

Yes, PDF.dk flattens PDF files online for free, no watermark and no signup.

Is it safe to upload my PDF?

Yes. Files are handled on Nordic servers, uploads are encrypted, and everything is wiped automatically a short while later. Nothing is stored, nothing is shared.

Flatten PDF

Flatten PDF forms and annotations online for free. Make content permanent.

Need to lock a filled-in form or make comments permanent? With PDF.dk you flatten your PDF for free — form fields, annotations and comments become a fixed part of the document and can no longer be changed. Your file is handled in the Nordics and removed automatically shortly after.

Frequently Asked Questions

What happens when flattening?: Forms, annotations and comments become a permanent part of the document and can no longer be edited.
When should I flatten a PDF?: Flatten a PDF before sharing if you want to prevent editing of form fields or comments.
How do I make a filled PDF form non-editable?: Upload the filled form and click Flatten. The field contents become ordinary page content, so recipients see the answers but cannot change them — useful before submission or archiving.
What does flattening a PDF mean?: Flattening merges the interactive layers — form fields, annotations and comments — into the page itself, so the document consists of fixed content only. The appearance is preserved, but the elements can no longer be edited.
Does flattening remove my comments?: No, they do not disappear — they become permanent. Comments and highlights are drawn into the page, so they remain visible but can no longer be moved, edited or deleted.
Is it free to flatten a PDF?: Yes, PDF.dk flattens PDF files online for free, no watermark and no signup.
Is it safe to upload my PDF?: Yes. Files are handled on Nordic servers, uploads are encrypted, and everything is wiped automatically a short while later. Nothing is stored, nothing is shared.

How to

Upload your PDF with forms or annotations
Click "Flatten PDF"
Wait while content is made permanent
Download your flattened PDF