Flatten PDF — Free Online Tool

Flattening a PDF is the operation of merging all interactive and overlay content — form fields, annotations, signatures, watermarks, multi-layer content — directly into the static page content stream. After flattening, a previously-fillable form becomes a static page where the filled values are part of the page itself. A previously-annotated PDF loses the ability to edit individual highlights or comments because they have been baked into the rendering. This is the right operation in three common scenarios. First, when you fill a form and want to ensure the values cannot be changed by the recipient — flatten and the values are permanent. Second, when you annotate a document and want the markup to display reliably in viewers that do not support annotations (some web previews, some mobile readers) — flatten and the markup is just part of the page. Third, when you need to send a PDF to a print shop or signing service that mandates flattened input. Our flatten tool runs Ghostscript to render every page (including all overlays and form fields) and writes the result as new page content. The output is structurally a regular PDF that anyone can open, but it no longer carries any editable form fields, annotations, or signature placeholders.