Flatten PDF
Lock all interactive form fields into permanent, static page content, then download the result — free, private, and processed entirely in your browser.
About the PDF Flattener
Our free online PDF flattener locks fillable form fields — text boxes, checkboxes, radio buttons, and signatures — directly into the page layout, turning an interactive form into a permanent, uneditable document. This is essential for preventing fraud, locking in a completed sign-off, and creating a secure copy for long-term archiving.
Unlike most online tools, flattening happens entirely inside your browser using the pdf-lib library — your PDF is never uploaded to a server. That means it's fast, works without an internet round-trip, and keeps your files completely private and secure.
How to Flatten a PDF
Step 1
Upload your fillable PDF
Drag and drop a PDF file that contains form fields, or choose one from your device.
Step 2
Click "Flatten PDF"
This locks every text box, checkbox, and form field into the page content permanently.
Step 3
Download the result
Download the flat, read-only PDF document instantly — no waiting, no watermark.
Frequently Asked Questions
What does flattening a PDF actually do?
Flattening merges the interactive form fields, checkboxes, and signatures directly into the page background. The result is a standard static document that looks identical but can no longer be edited or filled in.
Can I edit a PDF after it is flattened?
No. Once a PDF form is flattened, the interactive fields are removed and can't be recovered. Keep a backup copy of the original fillable version if you might need to make changes later.
Why would I want to flatten a PDF?
Flattening is useful for preventing fraud, locking in sign-offs and approvals, and creating a secure archival copy of a completed form that can't be tampered with.
Is my data safe?
Yes. Flattening happens entirely in your browser using the pdf-lib library — your PDF is never uploaded to a server, so it stays completely private.
Does it cost money?
No. The PDF flattener is 100% free to use, with no registration or account required.