# Fill and flatten a PDF form in C#

> Fill AcroForm text fields, check boxes, radio buttons and combo boxes in .NET, then flatten the values into the page. MIT licensed, pure C#.

Available since 1.1.

Fill an interactive PDF form from code, then make the values part of the page.

## Short answer

Look fields up by name in `doc.Form`, cast to the field type, and set the value. Setting a value
redraws the field's appearance, so the filled form looks the same in every viewer. `Flatten`
stamps the appearances into the pages and removes the form, so the values can no longer be edited.

```csharp title="recipe-fill-and-flatten-pdf-form.cs"
#:package PdfNetStack@1.2.0
using PdfNetStack;

PdfDocument doc = PdfDocument.Open("application.pdf");
((PdfTextField)doc.Form["name"]!).Text = "Jamal Abdelkhalek";
((PdfCheckBoxField)doc.Form["subscribe"]!).Checked = true;
((PdfRadioButtonField)doc.Form["plan"]!).Selected = "pro";
((PdfChoiceField)doc.Form["country"]!).Select("Morocco");
doc.Form.Flatten();   // values become page content, the form is removed
doc.Save("application-filled.pdf");
```

![The application form with a name, a checked box, the pro plan and Morocco filled in](https://www.jadev-corp.com/previews/recipe-filled-form.webp)

## Notes

- Field names are fully qualified: a field `city` inside `address` is `address.city`.
  `doc.Form.Fields` lists them all.
- Skip `Flatten` to keep the form editable after filling it.
- A font the form embeds whole is reused for the new appearance; others map to the closest
  standard font.

## Related

- [Forms](https://www.jadev-corp.com/guides/forms/): reading, filling, flattening and creating fields
- API: [PdfAcroForm](https://www.jadev-corp.com/api/pdfnetstack/pdfacroform/), [PdfTextField](https://www.jadev-corp.com/api/pdfnetstack/pdftextfield/), [PdfChoiceField](https://www.jadev-corp.com/api/pdfnetstack/pdfchoicefield/)

Source: https://www.jadev-corp.com/pdfnetstack/recipes/fill-and-flatten-pdf-form/