Open a PDF that already has AcroForm fields and enter your values: text boxes, check boxes, lists and radio groups are shown as controls. Keep the fields editable in the download, or flatten the form so the values become part of the page.
Runs locally in your browserOpen a PDF that already carries AcroForm fields: text boxes, check boxes, lists and radio groups are read and shown as controls. The file is parsed and rewritten in this browser, and nothing is uploaded.
Type the values you need, leave the rest alone, then download the form as an editable copy or flatten it so the values become part of the page content.
Text fields (single-line and multiline), check boxes, dropdowns, option lists and radio groups are read when the file loads and written when the run starts. A list keeps several selections when the PDF marks it as multi-select; a single-select list takes one value.
Read-only fields are shown with their value and locked, so they come out as they went in. A signature or push-button field is listed as read-only or unsupported and is left untouched unless you flatten the form.
With the switch off the output keeps the AcroForm, and every value can be edited again in a PDF reader. With the switch on the values are drawn into the page content and the fields are removed: the downloaded file carries no form fields at all.
A widget that has no appearance of its own - an unsigned signature field, for instance - gets an empty one before flattening, so a form that contains one can still be flattened. If a field cannot be merged at all, the download keeps the fields editable and the status line says so.
Field text is drawn with the font the PDF already uses. A standard Helvetica covers Latin-1 only, so CJK or emoji are refused with their own message instead of being written invisibly, while accented Latin text such as "Café Müller" is fine.
A value longer than the field’s own MaxLen limit is refused. A PDF with no AcroForm fields, an encrypted file and an empty or damaged file each answer with their own sentence, and the same file filled twice produces the same bytes.