What does flattening a PDF do?

Flattening converts interactive form fields, annotations, and layers into static content. The visual appearance stays the same, but fields can no longer be edited.

When should I flatten a PDF?

Flatten before sharing final documents, archiving forms, or when a recipient's PDF reader doesn't display form fields correctly. It ensures the document looks the same everywhere.

Do my files get uploaded?

No. Flattening is done entirely in your browser with pdf-lib. Your PDF never leaves your device.

Can I undo flattening after saving?

No. Flattening is permanent. Once form fields and annotations are converted to static content, they cannot be made interactive again. Keep a copy of the original if you might need it.

Does flattening reduce the file size?

It can. Removing interactive form field metadata sometimes reduces file size slightly. The difference depends on how many fields the original PDF contained.

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How it works

Upload your PDF

Drop your file with form fields or annotations.

Review the info

The tool explains what flattening does: form fields and annotations become static content.

Download flattened PDF

Click Flatten PDF and download a non-editable, universally compatible version.

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