Merge interactive form fields and annotations permanently into the static page content. Prevents further editing and ensures consistent rendering everywhere.
Flattening converts interactive PDF elements — form field values, annotations, signature fields, and comments — into static page content. After flattening, the document looks identical but no field can be edited, no annotation moved, and no signature field clicked. Flattening is permanent: always keep an unflattened copy if you may need to edit the document again.
Interactive form fields. Text fields, checkboxes, radio buttons, and dropdown menus filled in by the user are baked into the page as static text and graphics. The underlying field structure is removed.
Annotations. Sticky notes, highlight markups, text comments, and ink annotations are merged into the page layer. They can no longer be selected, moved, or deleted as separate objects.
Digital signature fields. Signature fields and their appearance are baked in. The resulting document still shows the signature visually, but the signature field is no longer interactive.
Layer visibility. Any optional content layers are merged into a single static page. Viewers can no longer toggle layers on or off.
Before sharing a completed form. After filling in a form, flatten it before sending so the recipient cannot alter your answers. The form data is preserved visually but cannot be changed.
Before printing. Some printers and print spoolers handle interactive PDF elements inconsistently, causing missing fields or layout errors in the printout. Flattening eliminates this risk.
Before archiving. Long-term PDF/A archiving standards require static content. Flattening prepares a document for compliant archival storage.
Fixing rendering inconsistencies. If a PDF looks different in Adobe Reader vs a browser vs a mobile viewer, the issue is often interactive layer rendering. Flattening produces a single static view that renders identically everywhere.
After adding a signature. Once a document has been signed by all parties, flatten to prevent anyone reopening and altering annotation layers above the signature.
Is flattening reversible?
No. Once a PDF is flattened, interactive elements cannot be restored. Always save a copy of the original before flattening if you might need to edit the document again.
Will the document look different after flattening?
No. The visual appearance is preserved exactly. Text, images, form values, annotations, and signatures all look the same — they are simply no longer interactive or separately selectable layers.
Is the file uploaded to a server?
No. Flattening runs entirely in your browser using JavaScript. Your document is never transmitted to any external server, making it safe to use with signed contracts, medical forms, and financial documents.
Does flattening affect file size?
It varies. Removing interactive form structures can slightly reduce file size. However, if annotations or comments were stored efficiently, their rasterisation into the page layer can increase size modestly. The difference is usually under 10%.
Can I flatten just one page?
The tool flattens the entire document. If you need to flatten only specific pages, consider splitting the PDF first, flattening the relevant portion, then merging back together.