Flatten PDF Online – Make Form Fields and Comments Permanent Free

How to Flatten a PDF

Choose your PDF. The tool counts its form fields, comments and links.
Under "What to flatten", keep both options or untick one, for example to flatten the form but keep the comments.
Click "Flatten and download". The new file is checked again, and the report shows whether anything is still interactive.

What flattening does

A filled-in form field or a comment is not part of the page. It lies on top of it, and anyone with a PDF reader can change it, delete it or hide it, and some viewers and printers do not show it at all. Flattening draws each of these items onto the page exactly where and how it appears, then removes the item itself.

Typed-in text, ticks and selected options look the same but can no longer be edited or cleared.
Highlights, notes, stamps, shapes and drawings stay visible in every viewer and on paper.
The page text itself is not touched, so it stays selectable and searchable, and links stay clickable.

When to flatten a PDF

Before sending a completed application, contract or tax form, so the answers cannot be changed by mistake.
When filled-in fields or comments disappear in another viewer, in a browser, on a phone or when printing.
Before merging or uploading forms to a portal that rejects interactive fields.
When review comments or stamps are final and should be part of the document.

Limits

Flattening cannot be undone in the new file. Keep the original if you may need to edit the form again.
An item is drawn from the appearance stored in the file. Items without one are left as they are and reported; this happens with some forms made by scripts. Opening and saving the file in a PDF reader usually adds the missing appearances.
Pop-up text of comments is removed together with the comment; only the visible mark stays on the page.
Flattened text is still in the file and can be copied. To remove information for good, use Redact PDF.
Password-protected PDFs must be unlocked first with Unlock PDF. A digital signature becomes invalid after flattening.

Flatten PDF – Frequently Asked Questions

What does it mean to flatten a PDF?

Form fields and comments are turned into ordinary page content. They look the same, but they can no longer be edited, moved or deleted in a PDF reader.

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

Fill in the form, save it, then choose it here with "Form fields" ticked and click "Flatten and download". The answers become part of the page.

Why do my filled-in fields disappear when I print or open the PDF elsewhere?

Some viewers and printers do not show form fields or comments. After flattening they are part of the page and appear everywhere.

Can I still select and search the text?

Yes. The pages are not turned into images: the original text stays selectable, and flattened form text stays in the file as text.

Can a flattened PDF be unflattened?

No. The form fields and comments no longer exist in the new file. Keep the original if you may need them again.

Is my PDF uploaded?

No. The file is opened and flattened by your browser on your own device.

Is it free?

Yes – no sign-up and no watermark.

Related tools: Sign PDF to add your signature, Protect PDF to add a password, and PDF to PDF/A to make an archive copy.

Explore the full collection of tools in the PDF Security Tools.

Flatten PDF – Make Form Fields and Comments Permanent

What to flatten

Finish your document