Flatten a PDF
Make filled-in forms and annotations a permanent part of the page. After flattening, answers can’t be changed in a normal PDF reader and the document looks the same everywhere.
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
Choose a filled-in form or an annotated document.
Choose what to flatten
Form fields, annotations, or both.
Flatten
Field values and markup are drawn into the page content.
Download
Save the flattened copy and send it on.
Key features
Locks in form answers
Typed text, ticked boxes and dropdown choices become fixed, so they can’t be altered by accident.
Consistent appearance
Some viewers show form fields differently. Flattened pages look identical in every viewer and when printed.
Bakes in markup
Highlights, stamps, ink drawings and shapes are merged into the page. Links keep working.
Clear report
You’re told how many fields and annotations were flattened, or if there were none.
When to flatten
Flatten a form after completing it and before submitting it, particularly if it will be printed, archived or passed to someone who shouldn’t change your answers. It’s also a good final step after signing or adding text.
Flattening isn’t encryption. Someone with editing software can still alter the page content, just as they could alter any PDF. To restrict opening, add a password with Protect PDF.
Security and privacy
Flatten PDF runs entirely in your browser. Your file is processed in this tab’s memory and never uploaded to PDF365 or anyone else. When you close the tab or press “Start over”, the data is discarded.
Read more in our privacy policy.
Questions about Flatten PDF
Can a flattened PDF be unflattened?
No. Once fields are flattened they’re ordinary page content. Keep the original if you might need to edit the answers later.
Do comments disappear when flattened?
The visible markers (such as highlights and note icons) stay on the page. The pop-up text of comments is not shown on the page, so check that nothing important lives only in a pop-up.
Why does the tool say nothing was flattened?
The PDF has no interactive form fields or visible annotations, which is common for scanned or printed-to-PDF documents. It is already “flat”.