Fields, overlays and XFA
Fillable PDFs use AcroForm fields. The engine fills them and draws each value’s appearance, so the text shows in every viewer, including ones that do not redraw fields. Read-only fields are left as the form’s author set them.
Some government PDFs are “XFA hybrids”: they carry a second, XML form layer that Adobe products show instead of the normal fields. This tool fills the normal AcroForm layer and tells you when XFA is present. Viewers like Chrome, Edge, Firefox and Preview show the AcroForm values; Adobe Acrobat may show the XFA layer, which stays empty unless you choose to remove it.
For official IRS and USCIS forms, use the form’s own page, which serves the current edition and its rules.
Steps
- Add the PDF.
- Fill the listed fields, or click the page to place text.
- Choose whether to flatten (lock) the result.
- Download.
Limits, stated plainly
- Fields that run calculations or validation scripts are filled as plain values; scripts are not run.
- Text placed on a page without fields uses Helvetica, which covers Latin characters only.
Engine: pdf-lib in a Web Worker; pdf.js preview. Your file is not uploaded; check it yourself.