Flatten a PDF (forms and comments)
FileReshape's Flatten PDF tool turns filled-in form fields and comments such as highlights, stamps and drawings into ordinary page content, so they look the same everywhere and can no longer be edited. It runs in your browser with pdf-lib, and the file is not uploaded. Links stay clickable, a digital signature stops being valid, and comments without an appearance of their own are left as they are.
Did a file not convert correctly? E-mail [email protected], ideally with a small sample file, and it will be fixed.
Key facts
- Works with: PDF (.pdf).
- Your files are not uploaded: the work is done in your browser, on your own device.
- File size: no fixed limit; very large files are limited by your device's memory.
- Needs a current browser (Chrome, Edge, Firefox or Safari) on a computer, tablet or phone; nothing to install.
- Free to use, with no sign-up.
Why flatten a PDF
A filled-in PDF form is still a form: the values sit in fields on top of the page, anyone can click into them and change a figure, and some programs show them blank or in another font, or drop them when the file is printed, merged or uploaded to a portal. Comments behave the same way, as a separate layer that a reader can hide, move or delete. Flattening draws each field and each comment into the page exactly as it is shown now and removes the interactive part, so a signed application, an invoice or a reviewed draft looks the same in every PDF reader and cannot be edited by accident. Choose what to flatten: the form fields, the comments and markup, or both. Text in the fields stays real text, so it can still be selected and searched, and the pages are not turned into pictures, which keeps the file sharp and small. The work is done by pdf-lib running in this page, so the document stays on your device. Keep the original if you might want to change an answer later, because a flattened copy cannot be turned back into a form.
How to flatten a PDF
- Drop your PDF in the box, or click to choose it.
- Tick form fields, comments and markup, or both.
- Click Flatten PDF and download the flattened copy; your original file is not changed.
What changes when you convert
A flattened form cannot be filled in again
The fields are gone in the copy, and their values are now part of the page like printed text. To change an answer, edit the original form and flatten it again. Keep the original next to the flattened copy, at least until the form has been accepted.
Comments without an appearance stay comments
Most PDF editors save how a highlight, a stamp or a drawing looks, and that look is what is drawn into the page. Some comments, often sticky notes from simple viewers, have no saved look at all; there is nothing to draw, so they are left in the file as comments and the result says how many.
Digital signatures and certified forms
Flattening changes the page content, so a digital signature in the file is no longer valid, and the page warns you when it finds one. Flatten the form first and sign the flattened copy, or keep the signed original when the signature matters.
Fields without a saved look and XFA forms
Some form programs leave it to the reader to draw a field's value. Those fields are drawn here in Helvetica, and the result says how many; a value Helvetica cannot show, such as Chinese text, is flattened as the file has it. Dynamic XFA forms made in Adobe LiveCycle are not supported; only their regular fields are flattened.
About the formats
PDF (Portable Document Format) was created by Adobe in 1993 and has been an ISO standard since 2008. A PDF looks the same on every device, which is why it is used for contracts, invoices, forms, manuals and scanned documents.
- A page can hold text, vector graphics and images, each placed exactly.
- Scanned documents are usually one image per page.
- A PDF can be protected with a password that is needed to open or edit it.
Frequently asked questions
Is my PDF uploaded?
No. The PDF is read and rewritten by pdf-lib inside this web page on your device, and nothing is sent to a server.
Can the text in a flattened form still be copied?
Yes. The values are drawn with the fonts the fields already used, as text, so they can be selected, copied and found with search. Flattening does not turn the pages into images.
What happens to links and attachments?
Web links and links inside the document stay clickable, and files attached to the PDF stay attached. Only form fields and comments with a visible look of their own are flattened.
Why does a portal reject my filled-in PDF form?
Many upload portals, print shops and e-mail scanners only read the page content and ignore form fields, or refuse files that can still be edited. A flattened copy shows the same values in the page itself, which is what those systems expect.