Bake form fields, signatures and annotations into the page so they can’t be edited. All on your device.
Flattening merges interactive elements — form fields, signatures, stamps and annotations — into the page itself, so recipients can read but not alter them. PDFZero offers two modes: a lossless form-field flatten that keeps text selectable, and a full rasterize that bakes absolutely everything into the page image. Both run entirely in your browser.
Flatten before emailing filled applications, signed agreements or annotated review copies — it prevents accidental (or deliberate) edits to what you wrote. Note that flattening is about integrity, not secrecy: to hide information, use Redact PDF, and to restrict opening, use Protect PDF.
It converts interactive elements — form fields, signatures, annotations — into permanent page content that can no longer be clicked, edited or moved.
Use "Form fields only" for filled forms: it’s lossless and keeps text crisp and selectable. Use "Everything" when you also need stamps, drawings and signatures baked in — pages are re-rendered as images.
No. Both modes run locally — pdf-lib flattens the form, and PDF.js re-renders pages for full mode. The file never leaves your device.
It prevents edits to fields and annotations, but it doesn’t encrypt the file or hide content. Combine it with Protect PDF (password) or Redact PDF (remove sensitive text) as needed.