Flatten PDF
Flatten interactive form fields in a PDF into permanent, non-editable content. Upload a filled-in PDF form and download a locked, flattened version.
Click to upload a PDF file
Your file is processed entirely in your browser
Recommended Settings
Pro Tips
- •Flattening converts interactive fields (text boxes, checkboxes, radio buttons, dropdowns) into fixed page content that can't be edited
- •The visual appearance of filled-in fields is preserved exactly - only their editability is removed
- •This is a one-way operation - once flattened, a PDF's form fields can't be restored without the original file
- •The whole file is processed locally in your browser using pdf-lib - nothing is uploaded anywhere
Most Popular
Most users flatten a completed form right before archiving or sending it to prevent further edits
When to Use This Tool
Lock a filled-out PDF form so the entered data can't be accidentally changed by whoever opens it next.
Convert a completed application, contract, or survey form into a permanent record before storing it long-term.
Flatten form fields before printing, since some printers or print-to-PDF workflows handle static content more reliably than interactive fields.
Send a filled-in form to someone else without giving them the ability to modify the answers you've already entered.
How It Works
Read the uploaded PDF file as binary data directly in your browser and detect any interactive form fields
Load the file into a PDF document using the pdf-lib library
Call pdf-lib's form flattening function, which converts each field's current value into static page content
Save the modified PDF, now without any editable form fields, and trigger a download
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by pdf-lib for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
What does 'flattening' actually do?
It takes every interactive form field's current value (whatever text was typed, which checkboxes were checked) and burns it into the page as regular, non-editable content. The field widgets are then removed, leaving only their visual appearance behind.
What happens if my PDF has no form fields?
The tool will detect that there are no fields to flatten and show an error rather than producing an unchanged file, since there's nothing to do.
Can I undo flattening?
No. Flattening permanently removes the interactive form fields from the saved file. Keep a copy of your original PDF if you might need to edit the form again later.
Is my PDF uploaded to a server?
No. The entire file is read, flattened, and re-saved locally in your browser using the pdf-lib library. Your document never leaves your device.
Does flattening change how the document looks?
No. The visual appearance of the filled-in form is preserved exactly as it was - flattening only affects whether the fields remain editable.