Lock AcroForm field values into the page so the form can no longer be edited.
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Lock AcroForm field values into the page so the form can no longer be edited. Works with multiple files at once.
Fillable PDFs can have their values changed after signing. CipherForces PDF Flatten uses pdf-lib’s form-flatten operation to bake every AcroForm field value into the page content so no one can edit it anymore. This is the standard step before sending a signed PDF to counterparties.
What this tool does not do: it does not remove or rewrite markup annotations (highlights, sticky notes, text comments, stamps, or freehand drawings). Those remain in the file as-is. To strip markup, use Print → Save as PDF or a PDF editor that exposes individual annotations.
Privacy: All processing happens in your browser via pdf-lib. No upload.
Open the Flatten PDF Form tool, drag in your filled PDF, and click flatten. It locks every AcroForm field value into the page and returns a new file. Anyone who opens it sees your entries as fixed text or graphics, no longer editable form fields.
No. This tool runs entirely in your browser using JavaScript, so the file never leaves your device or uploads anywhere. There is no signup and nothing is stored. That keeps signed contracts, tax forms, and other sensitive PDF documents private to your own computer.
Yes. Fill in the AcroForm fields in your usual PDF reader first, save the file, then load it here to lock those values. The text, checkboxes, and selections you entered become part of the page so the recipient sees them exactly as filled.
Flattening prevents accidental or deliberate changes to your filled form. Once the fields are locked into the page, recipients can read and print the values but cannot alter them, which helps preserve agreements, applications, and invoices the way you submitted them.
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