How to use it
- Choose the PDF form. The number of form fields appears under the file name. A file without form fields is refused.
- Click Flatten form. The answer in each field is drawn into its page, and the fields are removed.
- Click Download to save the new PDF, then open it once to check the answers before you share it.
What flattening changes
A fillable PDF keeps its form fields apart from the page. The answer in a field is data that a viewer draws, so anyone with a form viewer can change it. Flattening draws the picture that each field has in the file into its page, then removes the fields and the form. A field whose picture is older than its answer keeps that older picture, as a viewer shows it.
The pages keep their text, images, links and comments. Only the form fields and the form itself are removed, so the answers cannot be edited afterwards.
Forms this tool does not flatten
A form is refused, and the message says why, in these cases. Each one is listed here so that you know what to expect before you choose a file.
- No form fields: the file has no fields to flatten.
- XFA data: an Adobe form format that the library in your browser cannot read or write, so the form is refused rather than flattened without its data.
- No picture for an answer: a field holds an answer but the file has no picture of it, so the answer cannot be drawn. The message names the field.
Example: a form with a name and a city
A form has two fields, Name and City, and the Name field holds the answer Ada. The tool reports 2 form fields, and 2 places on the page where they show.
After flattening, the file has the same page with the answers drawn into it, no form fields left, and the text of the page unchanged.
Frequently asked questions
Are my PDF files uploaded anywhere?
No. Your browser reads the form, draws the fields into the pages and makes the new file on your own device. Nothing is sent to our server.
Can I still change the answers after flattening?
No. Once the fields are drawn into the page, a form viewer has no field left to type into. Keep the original file if you may need to change an answer later.
Why does the tool refuse my form?
A file with no form fields, an XFA form, an encrypted file or a damaged file is refused, and the message says which. Text with letters the standard font cannot write, such as Turkish ş or Cyrillic, is drawn as a picture in its field, so it is not refused.
Does flattening remove the text of the pages?
No. The text of the pages, the images, the links and the comments are kept. Only the form fields and the form itself are removed.
Is this the same as filling in a form?
No. Filling in a form writes answers into its fields. This tool takes a form whose answers are already in it and makes them permanent; the form filling tool can fill a form and flatten it in one step.
Sources
- pdf-lib, the open-source library that reads the form and flattens it in your browser; its documentation describes what flatten() removes
- pdf-lib documentation: reading and changing PDF forms
Figures and text last checked on Thursday, November 12, 2026.