Flatten PDF
Lock PDF form fields and annotations so they can no longer be edited.
Key Capabilities
What does it mean to flatten a PDF?
Flattening a PDF locks all interactive elements, such as form fields and annotations, merging them permanently into the visual background of the document. This prevents anyone from modifying the text later.
Is my document secure?
Yes. The flattening process runs 100% locally in your browser. Your sensitive files and form data are never uploaded to our servers.
How to Use
Upload your PDF
Open the Flatten PDF | Lock PDF Forms Online Free tool and upload your PDF file. You can drag-and-drop or click to browse. Multiple files may be supported depending on the tool.
Configure options
Adjust the tool settings as needed (page range, quality, output format). The preview updates in real-time.
Download processed PDF
Click "Download" to save your processed PDF. All processing happens client-side — your files never leave your device.
Frequently Asked Questions
What does it mean to flatten a PDF?
Flattening a PDF locks all interactive elements, such as form fields and annotations, merging them permanently into the visual background of the document. This prevents anyone from modifying the text later.
Is my document secure?
Yes. The flattening process runs 100% locally in your browser. Your sensitive files and form data are never uploaded to our servers.
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