Flatten PDF - Lock Form Fields and Comments
Lock filled forms, comments and stamps into the page so they can no longer be changed.
How to use Flatten PDF
- Click Select and choose your PDF, or drop it anywhere on the page.
- Set the options in the panel on the right.
- Click Flatten PDF. The result is created in your browser and downloads straight away.
Tip: "Form fields" keeps text selectable; "Everything" also burns in comments but saves pages as images.
Frequently asked questions
Why flatten a PDF?
Flattening stops recipients changing values you filled in and makes the file look the same in every viewer.
Is Flatten PDF free?
Yes. All 48 tools on Chutki are free to use, with no sign-up and no watermark added to your files.
Are my files uploaded to a server?
No. Your files are processed inside your own browser and never leave your computer, which makes the tool suitable for confidential and client documents.
Does it work on mobile?
Yes. It works in current versions of Chrome, Edge, Firefox and Safari on computers, tablets and phones. Very large files work best on a computer.