You've got a PDF with form fields, annotations, or multiple layers. You want to share it, but you don't want anyone editing it. Flattening merges everything into a single layer — it's like baking a cake so you can't separate the ingredients.
What does flattening do?
- Merges layers: All content becomes a single image-like layer.
- Locks form fields: Form fields become static text.
- Removes annotations: Comments and sticky notes are merged into the page.
- Prevents editing: The PDF can't be easily edited.
How to flatten a PDF
- Open PDFly's Flatten PDF tool.
- Upload your PDF.
- Choose whether to flatten form fields and annotations.
- Click process and download your flattened PDF.
When to flatten a PDF
- Finalizing documents: Lock a document before sharing.
- Legal contracts: Prevent unauthorized changes.
- Archiving: Create a static version of a document.
- Printing: Ensure everything prints correctly.
Frequently Asked Questions
Can I unflatten a PDF?
No — flattening is permanent. The content is merged into a single layer.
Does flattening reduce file size?
It can, because it removes editable elements. But the file size might stay similar.
Can I flatten a PDF on my phone?
Yes — browser-based tools work on any device with a browser.