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PurePDF

Flatten PDF

Merge form fields and annotations into the page content permanently.

  • 100% Private
  • No Limits
  • Works Offline
Choose PDF file

or drag and drop here

Lock in a PDF's form fields and annotations so they become part of the page content and can no longer be edited or filled in. Runs locally in your browser.

How to use this tool

  1. 1

    Upload your PDF

    Click the upload area or drag in a document with form fields or annotations.

  2. 2

    Flatten and download

    Click flatten — your document downloads immediately, no options needed.

Why use this tool

Nothing leaves your device

Flattening happens locally via WebAssembly — your document is never uploaded.

Prevents further edits

Once flattened, form fields can't be accidentally changed by the next person who opens it.

Consistent appearance everywhere

Flattened content renders the same in every PDF viewer, unlike some live form fields.

Common use cases

Finalize a filled-in form

Lock in your answers before sending a completed form to someone else.

Lock in a signature

Make sure a signature placed on a document can't be moved or deleted.

Prepare for archiving

Flatten interactive elements before storing a document long-term.

Pro tips

  • Flattening is one-way — keep a copy of the original if you might need to edit the form again later.
  • A PDF with no form fields or annotations is returned unchanged — flattening is safe to run on any file.
  • Sign PDF and Fill PDF Form both work well together with Flatten PDF as a final step.

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