Flatten PDF
Make form fields permanent so filled-in answers can't be changed.
Your files stay on this device
or drop them here, or paste with Ctrl+V
PDF · up to 20 files · stays on your device
How to use Flatten PDF
- 1Add one or more files — drag and drop or tap to choose. Accepted: PDF.
- 2No settings needed.
- 3Press “Flatten PDF”. Processing happens on your device.
- 4Download your PDF, one by one or all together as a ZIP.
About this tool
Make form fields permanent so filled-in answers can't be changed. Your files are processed locally in your browser, so they're never uploaded, queued or stored — which also makes it fast. It's part of our free pdf tools, which work together — you can pass the result straight into related tools below.
- Accepts
- Gives you
- Files at once
- Up to 20
- Processed
- On your device
Frequently asked questions
Is Flatten PDF free?
Yes. There's no sign-up, no watermark and no usage limit.
Are my files uploaded to a server?
No. Flatten PDF runs entirely in your browser. Your files never leave your device and nothing is stored — close the tab and everything is gone.
Which file types can I use?
PDF. Files are checked by their actual content, not just the extension, so renamed or damaged files are caught early.
Is there a file size limit?
Each file can be up to 200.0 MB, and you can process up to 20 files at once. Because processing uses your device's memory, very large files work best on a computer.
Does it work on my phone?
Yes. It works in modern mobile browsers on Android and iPhone. Heavier jobs (large PDFs, OCR) are faster on a computer.