Flatten PDF
Flatten a PDF free — bake fillable form fields into the page so their values become permanent and can't be edited. Private, in your browser.
About the Flatten PDF
Flattening merges a PDF's interactive form fields — text boxes, checkboxes, radio buttons and dropdowns — into the static page content. After flattening, the values are locked in and can no longer be changed, which is exactly what you want when finalising a filled form before emailing or archiving it.
It also helps with compatibility: some viewers render form fields inconsistently, and flattening guarantees every reader sees the same result. The tool reports how many fields it flattened so you know it worked.
The document is processed on your device with pdf-lib, so nothing is uploaded. There are no watermarks, no page limits and no sign-up.
How to Use the Flatten PDF
- 1Upload the PDF form you want to finalise.
- 2Click Flatten PDF.
- 3Check how many fields were flattened.
- 4Download the flattened, non-editable PDF.
Frequently Asked Questions
What exactly does flattening do?
It draws the current value of every form field directly onto the page and removes the interactive field, so the content becomes a permanent part of the document. Recipients see the filled values but can no longer edit them.
My PDF has no form fields — will flattening change it?
If there are no fillable fields, there is nothing to flatten; the tool simply re-saves a clean copy and reports zero fields flattened. The visible content is unchanged.
Does flattening prevent all editing?
It locks form-field values and merges annotations into the page, but it is not encryption — someone with a professional editor could still alter the page. Use it to finalise forms and ensure consistent rendering, not as security.
Is my PDF uploaded?
No. Flattening runs entirely in your browser with pdf-lib and the file never leaves your device.