Flatten PDF Online
Lock form answers, comments and stamps into the page so nobody can change them.
Upload a PDF to Flatten
Drag & drop your file here, or click to browse
Your flattened PDF is ready!
How to Flatten a PDF in 3 Easy Steps
Make a filled form or annotated PDF permanent — free and private.
Choose Your PDF
Click Choose PDF File or drag your PDF into the box.
Pick What to Flatten
Flatten form fields and/or comments — or choose Pages to images for the strongest lock.
Flatten and Download
Click Flatten PDF and download your locked PDF.
Why Use Toolszu Flatten PDF
Make sure what you send is exactly what they see.
Lock Form Answers
Filled-in fields become normal page content that can't be edited.
Flatten Annotations
Comments, highlights, stamps, drawings and signatures become part of the page.
Pages to Images
The strongest option: every page becomes a picture — nothing can be selected or edited.
Prints Correctly
Flattened forms print and display the same in every app and on every printer.
No Upload
Your document is processed on your device.
Free, No Watermark
No sign-up and nothing added.
When to Flatten a PDF
Final documents should stay final.
Signed Contracts
Make sure signatures and filled fields can't be moved or changed.
Official Submissions
Many portals ask for flattened forms.
Printing Problems
Fix forms whose answers disappear when printed.
Viewing on Phones
Some phone viewers hide form answers or comments — flattened PDFs always show them.
Reviewed Documents
Lock in comments and highlights before sharing a reviewed file.
Before Merging
Flatten forms before merging so the answers are kept.
Tips for Flattening PDFs
- Keep a copy of the original — flattened answers can't be edited any more.
- Want to fill the form first? Use Fill PDF Form (it can flatten too).
- Also want to stop copying? Choose Pages to images, or add a password with Protect PDF.
Frequently Asked Questions
Quick answers about flattening PDFs.
Flattening turns interactive parts — form fields, comments, highlights and stamps — into normal page content. The document looks the same, but those parts can no longer be edited or removed.
Choose your PDF, pick what to flatten and click Flatten PDF. Then download it. It's free and needs no sign-up.
Yes, with Flatten forms & comments. With Pages to images every page becomes a picture, so text can't be selected or copied.
Yes. Clickable links stay clickable when you flatten forms and comments.
No. Everything happens inside your web browser, on your own device. Your file is never uploaded, stored or seen by anyone.
Remove the password first with our free Unlock PDF tool (you'll need the password), then use the unlocked file.
Yes. It works in Safari, Chrome and other mobile browsers on iPhone and Android — no app needed.
Yes, it's 100% free. There's no sign-up, no premium version and no watermark or Toolszu logo added to your file.
Related Free PDF Tools
Fill PDF Form
Fill in PDF forms online
Sign PDF Online
Add your signature to a PDF
Protect PDF
Add a password to your PDF
Edit PDF Online
Change PDF text in the same font
Compress PDF
Reduce PDF file size online
Merge PDF
Combine multiple PDFs into one
PDF to JPG
Convert PDF pages to JPG images
Organize PDF
Reorder, rotate and delete pages
Unlock PDF
Remove a PDF password