PDF flattening merges all interactive layers — form fields, annotations, signatures, comments — into the static page content. Here is when and why to use it.
An unflattened PDF has interactive layers: form fields that can be edited, annotations that can be moved, signature fields that can be replaced. Flattening merges all layers into the permanent page content — making the document final and uneditable.
Flatten when: submitting a signed contract (prevents signature replacement), archiving completed forms (prevents future editing), preparing for printing (ensures annotations print correctly), sending for certified copying (preserves the exact document state).
Go to pdfeditor.onl/pdf-studio. Open the PDF. Use the Flatten option in the download/export settings. The output PDF has all interactive elements permanently embedded.
Tip: Always keep a copy of the original (unflattened) PDF before flattening. Flattening is irreversible — the form fields and annotations cannot be recovered after the file is flattened.
Functionally similar — both produce a static page image. Flattening at the PDF level is cleaner as it preserves vector text and graphics quality without rasterization.
Yes — completely free at pdfeditor.onl/pdf-studio.