Files never leave your device.How it works
How to flatten a PDF
- 1Drop your PDF above (or click to select).
- 2Click Flatten — the interactive form fields are merged into the page.
- 3Download the flattened PDF.
Frequently asked questions
- What does flattening do?
- It merges a PDF's interactive form fields into the page content, so the values look the same in every reader and can no longer be edited or cleared. It's the way to finalise a filled form before sharing it.
- Do my files get uploaded anywhere?
- No. Flattening happens entirely in your browser — your PDF never leaves your device.
- What if my PDF has no form fields?
- Then there's nothing to flatten and the file is saved unchanged. Flattening applies to AcroForm fields; free-floating annotations aren't merged.
- Can I still edit it afterwards?
- Not the flattened fields — that's the point. Keep an unflattened copy if you might need to change the values later.
Make a filled form final
A filled PDF form is still editable — anyone can open it and change your answers. Flattening merges those form fields into the page itself, so the values become part of the document: fixed, consistent in every reader, and no longer editable. It's how you turn a working form into a final copy before you send it.
Simple and local
There's nothing to configure — drop the PDF, flatten it, download. The whole thing runs in your browser, so a form full of personal details never leaves your device. Flattening applies to a PDF's AcroForm fields; if there are none, the file is saved as-is.
Good to know
Keep an unflattened copy if you might need to update the values later, since flattened fields can't be edited again. To fill a form before flattening it, use Fill PDF Form; to strip the file's hidden details too, use Edit Metadata.
What flattening actually merges
A fillable PDF form stores its field values separately from the page's visible content — the text you typed lives in the AcroForm structure, and the reader draws it on top at display time. Flattening takes that separate value and bakes it directly into the page's content stream, the same layer the original page graphics live in, then removes the AcroForm entry entirely. After that, there's no field left to select, tab into, or clear.
Why this matters for sharing
An unflattened form can look different depending on the reader — some show a highlighted box around empty fields, some render fonts slightly differently — and worse, the values can still be changed by whoever receives it. Flattening removes both problems: the document renders identically everywhere, and what you filled in is what stays there.
Typical use
Flatten a signed rental application before emailing it, a completed tax form before printing it, or any form-based record you're archiving, where you want certainty that the saved values can never quietly change.