Lock the answers in a filled PDF form before you send it
Processed in your browser. Nothing is uploaded. Updated on 24 Oct 2026.A filled-in PDF form still has live fields: whoever opens it can change a figure, untick a box or clear a signature line, and some phone viewers show the fields empty. Flattening draws each answer into the page itself and removes the form, so the copy you send shows the same values everywhere and nobody can edit them. Comments are kept as comments on this page; the file never leaves your device.
Fill in the form in your PDF reader and save it.
Drop the saved PDF here and press Flatten.
Download the flattened copy and send that one: the answers show and print, but cannot be edited.
Flatten PDF turns a filled-in or commented PDF into a plain document. The values in each form field and the marks of each comment become part of the page, exactly where they were, and the fields themselves are removed.
A filled PDF form still has live fields: whoever receives it can change an amount or untick a box, and some phone viewers show the fields empty. A flattened copy shows the same answers in every viewer and printer, and nobody can alter them, which is why it is the usual last step before sending a form.
Every field carries a picture of how it looks, called its appearance. The tool places that picture into the page content at the field's exact position and size, the same way a PDF viewer does, so typed text, tick marks and chosen options look identical before and after flattening.
The rest of the article, and all 6 questions about Flatten PDF, are on the Flatten PDF page.
Flattening a PDF draws its form fields and comments into the page content and removes the interactive parts. The typed values, ticks and marks still show and print exactly as before, but nobody can edit them any more, because they are now part of the page rather than fields.
Fill in the form in your PDF reader and save it, then drop the saved file on this page and press Flatten. Download the flattened copy and send that one. Every answer stays visible in the same place, but the fields are gone, so the values cannot be changed.
Yes. Choose Form fields only before pressing Flatten. The form fields are drawn into the page and removed, while highlights, sticky notes and other comments stay as comments that can still be opened, read and replied to. Links are always kept working in either mode.
No. Once flattened, the values are part of the page drawing and the form structure is removed, so there is nothing left to switch back on. Keep the original fillable PDF if you may need to change an answer later, and send the flattened copy.
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