What does 'flattening' actually mean?

It converts interactive form fields — text boxes, checkboxes, dropdowns — into fixed content that looks the same but can no longer be edited or filled in. The visible answers stay exactly as they were.

Can I fill the form in here first?

Yes — every text box, checkbox, dropdown, radio group and list in the PDF is shown as a normal form. Only the fields you change are updated.

Can I fill a form without locking it?

Yes — switch off 'Lock the form when done' and your answers are saved into a PDF that stays fillable.

Can it flatten comments, highlights and stamps too?

Yes. Highlights, notes, text boxes, stamps, drawings and shapes that carry a stored appearance are drawn into the page itself, so a recipient can't move or delete them. Hidden annotations are removed. Links stay clickable.

Why were some annotations left as they were?

A few annotations store no picture of themselves — the viewer draws them on the fly — so there is nothing reliable to bake in. The page tells you how many were left, instead of guessing.

What happens if my PDF has no fillable fields or markup?

You'll get a clear message instead of an unchanged file — there's nothing to flatten. (Scanned forms are pictures; use Add Text to type onto them.)

Why did it say my text contains unsupported characters?

Forms use standard PDF fonts, which can't draw every character (for example emoji or some non-Latin scripts). Plain letters, numbers and common accented letters work.

Is locking reversible?

No — once flattened and downloaded, the answers are permanently part of the page in that file. Keep your original if you might need the fillable version again.

PDF Tool

Flatten PDF

Lock a PDF so it can't be edited: fill in its form fields and bake the answers in, and turn comments, highlights and stamps into fixed page content. Runs entirely in your browser.

UploadConfigureProcessingDownload

Drag a PDF here, or click to browse

Single file · Max 100.0 MB

How it works

1
Upload a PDF with fillable form fields, comments, highlights or stamps — form fields appear as a form you can fill in right here.
2
Type your answers, tick the boxes and pick from the dropdowns. Fields that already have answers show them.
3
Choose what to lock: the form, the comments and markup, or both — then apply.
4
Download the finished PDF.

Flatten PDF — frequently asked questions

What does 'flattening' actually mean?: It converts interactive form fields — text boxes, checkboxes, dropdowns — into fixed content that looks the same but can no longer be edited or filled in. The visible answers stay exactly as they were.
Can I fill the form in here first?: Yes — every text box, checkbox, dropdown, radio group and list in the PDF is shown as a normal form. Only the fields you change are updated.
Can I fill a form without locking it?: Yes — switch off 'Lock the form when done' and your answers are saved into a PDF that stays fillable.
Can it flatten comments, highlights and stamps too?: Yes. Highlights, notes, text boxes, stamps, drawings and shapes that carry a stored appearance are drawn into the page itself, so a recipient can't move or delete them. Hidden annotations are removed. Links stay clickable.
Why were some annotations left as they were?: A few annotations store no picture of themselves — the viewer draws them on the fly — so there is nothing reliable to bake in. The page tells you how many were left, instead of guessing.
What happens if my PDF has no fillable fields or markup?: You'll get a clear message instead of an unchanged file — there's nothing to flatten. (Scanned forms are pictures; use Add Text to type onto them.)
Why did it say my text contains unsupported characters?: Forms use standard PDF fonts, which can't draw every character (for example emoji or some non-Latin scripts). Plain letters, numbers and common accented letters work.
Is locking reversible?: No — once flattened and downloaded, the answers are permanently part of the page in that file. Keep your original if you might need the fillable version again.