pdfMB

Flatten PDF

Turn form fields and comments into a permanent part of the page, so they can’t be changed any more. Your file stays on this device.

  • No uploadYour file stays on this device.
  • Your original stays as it isYou download a new copy. Your file is never changed.
  • Free, no sign-upNo account and no daily limit.

What happens to your file

Everything below happens inside your browser, on your own device. The PDF is never uploaded, so nobody else, including us, can see it.

  1. Your browser reads the PDF and counts the form fields, comments, links and hidden items on every page.
  2. Every field and comment is drawn onto its page exactly where it was, in the same order the PDF viewer draws them, and then removed as a separate object.
  3. Fields that have no appearance of their own, or whose file asks the viewer to draw them, are drawn by pdfMB with a font that has every letter used: Helvetica for English, Sarabun for Thai, Vietnamese and other Latin letters.
  4. Highlights, underlines, shapes, lines and drawings without an appearance are drawn from their own colour, position and thickness.
  5. Hidden items and comment pop-ups are not drawn. Redaction marks that were never applied are kept, because drawing them would hide text that is still in the file.
  6. The form itself, its Adobe XFA copy and everything that pointed to the removed fields are taken out of the file.
  7. When it is done, pdfMB opens the new file again and counts what is left, so you can see that nothing editable remains.
In short
  1. Choose a PDF
  2. Check what will be flattened
  3. Press “Flatten”
  4. Download

How to flatten a PDF

  1. Choose a PDF. pdfMB lists how many form fields, comments and links it has.
  2. Choose what to flatten: form fields, comments and markups, or both. Links stay clickable unless you turn that off.
  3. Press “Flatten PDF”. Each field and comment is drawn onto its page and removed as an editable item.
  4. Check the preview of the first page and the result of the check, then download the new PDF.

When people use it

Send a filled form that can’t be changed

After filling an application or a contract, flatten it so the answers can’t be edited by anyone who receives it.

Make comments show everywhere

Some apps and printers skip comments, highlights and form answers. Once they are part of the page, every app shows and prints them.

Fix forms that look blank in some apps

Forms filled in some apps show empty boxes or broken Thai in other apps. Flattening draws the answers onto the page so they look the same everywhere.

Prepare a file for printing or archiving

Print shops and archive systems often ask for files without form fields or comments.

What it can’t do

  • Flattening cannot be undone in the new file. Keep the original if you may need to change the answers later.
  • It is not a way to remove private information. Text in the fields and comments can still be copied from the page. Use Redact PDF for that.
  • The text inside comment pop-ups is not kept, only what is visible on the page.
  • Forms made only in Adobe XFA format can’t be flattened here. They need Adobe Reader.
  • A digital signature in the file will no longer be valid, because the file has changed.
  • Password-protected PDFs cannot be opened. Remove the password first.

Questions about flattening PDFs

What does “flatten” mean?

A PDF can have items that sit on top of the page and can still be edited: form fields, highlights, notes, drawings and stamps. Flattening draws them onto the page itself and removes the editable items.

Will my Thai answers look right?

Yes. If a field has no appearance or the file asks the viewer to draw it, pdfMB draws it with a Thai font, with tone marks in the right place. Fields that already look right keep their own appearance.

Can I keep the links working?

Yes. “Keep links clickable” is on by default. Turn it off if you want the links removed too.

Can people still copy the text?

Yes. Flattening keeps text as text. It stops people from changing the answers in a form, but it does not hide anything.

Can I flatten only the form and keep the comments?

Yes. Untick “Comments and markups” and only the form fields are flattened. Or the other way round.