Flatten a PDF
Lock in what’s been filled in. Flattening turns form fields, comments, highlights and stamps into ordinary page content, so they look the same everywhere and can’t be changed.
- 1Add your file
- 2Make it yours
- 3Download & done
Let’s start with your file.
Drop your PDF here. We’ll take it from there.
PDF documents·Or drag and drop a file
Choose a different fileYour files stay on this device. Always.
How to flatten a PDF
- Choose a PDF. PDF1 tells you how many form fields and comments it found.
- Pick a method: keep text sharp, or turn pages into images.
- Press Flatten PDF and download.
Good to know
Keep text sharp uses the open-source qpdf engine to draw each field’s and comment’s appearance into the page and then remove the interactive layer. The page looks the same, text stays selectable, and nothing can be typed into the fields any more.
Turn pages into images redraws each page as a picture. Nothing on it can be selected or edited, which is the strongest kind of flattening, but text can no longer be searched or copied.
When to flatten
- Sending a completed form. Some form fields display differently, or even appear empty, in phone apps and browsers. Flattening makes your answers show up everywhere.
- Before printing. Some printers and print services skip form fields and comments. Flattened content always prints.
- Before merging. Merging PDFs whose fields share names can mix up their values. Flatten each form first.
- Final versions. Stop casual edits to an agreed document, a filled application or a reviewed draft with its comments.
Flattening is not redaction. Text under a comment or highlight stays in the file. To remove information, use Redact PDF.
Questions
Is my file uploaded anywhere?
No. PDF1 runs the whole job inside your browser tab with JavaScript and WebAssembly. The page has no upload endpoint, and its security policy blocks connections to other servers, so the file stays on your device. You can even disconnect from the internet once the page has loaded.
Can a flattened PDF be unflattened?
No. The form fields and comments are replaced by plain page content. Keep the original if you might need to edit it again.
Will my signature be flattened?
A signature placed as an image or a stamp is flattened with everything else. A certificate-based digital signature is invalidated by any change to the file, so flatten before signing digitally, not after.
The fields were empty after flattening. Why?
Some apps store field values without drawing them. PDF1 generates the missing appearances before flattening, which fixes most cases. If a field still looks wrong, try the image method.