Lock (flatten) a PDF form
Lock a filled-in PDF form before sending it, so the recipient can no longer edit the fields.
How it works
Once a PDF form has been filled in (personal information, checked boxes, signature), it's often best to send it in a form that can no longer be edited by the recipient. This tool removes the interactive fields of the document (text boxes, checkboxes) as well as the PDF's overall form declaration, so PDF readers no longer display editable fields.
Important: do entered values remain visible after locking?
In the vast majority of cases yes, because software that fills in a PDF form generally saves a fixed image ("appearance") of the value entered in each field, and this image stays displayed on the page even once the field is removed. If your PDF was filled in by a tool that does not save this fixed appearance, a value entered might no longer appear after locking: always check the result before sending it.
Can the form still be edited after locking?
The interactive input fields are removed, which prevents simple editing via a standard PDF reader. This is not, however, cryptographic protection: for stronger protection (password, edit restriction), combine this tool with our password protection tool.
100% local processing in your browser (WebAssembly) — your document's content is never sent to a server.