What does flattening a PDF form do?

Flattening takes interactive form widgets (text inputs, checkboxes, dropdowns, signatures) and permanently draws their visible values into the page content stream, removing the interactive field layer so entries cannot be altered.

Can flattened form fields be edited or changed later?

No. Once flattened, form fields become static page graphics and cannot be edited with standard PDF form filler software.

What happens to digital signatures when flattening?

The visual appearance of any placed signature is preserved on the page, but the cryptographic digital signature container is removed because the document content stream is modified.

Does this tool support Adobe XFA forms?

Standard AcroForm PDF forms are fully supported. Proprietary XML-based Adobe XFA forms cannot be flattened directly in the browser; use Adobe Acrobat or print to PDF for XFA files.

Are my sensitive forms uploaded to external cloud servers?

No. KissThePDF flattens your PDF locally inside your browser memory using WebAssembly. Your confidential financial and personal data never leaves your device.

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