Supported PDF Form Fields

PSPDFKit supports most form types defined by the PDF specification. We have to differentiate between field objects and annotation objects.

Type Field Object Annotation Object
Checkboxes CheckBoxFormField WidgetAnnotation
Radio Buttons RadioButtonFormField WidgetAnnotation
Push Buttons ButtonFormField WidgetAnnotation
List Boxes ListBoxFormField WidgetAnnotation
Combo Boxes ComboBoxFormField WidgetAnnotation
Text TextFormField WidgetAnnotation
Signatures SignatureFormField WidgetAnnotation

Field objects have no visual representation of their own and are represented by FormField, while annotation objects are visual representations of a single control inside a form field and are represented by WidgetAnnotation.

To render a WidgetAnnotation, the associated FormField will be accessed via the WidgetAnnotation#formFieldName property. Based on the type of this FormField, different form controls are rendered.

We currently render generic elements for every form field type. Rendering the custom appearance stream for form fields is planned for a future release.

We also allow creating a FormField and a WidgetAnnotation directly from a loaded instance, and this is described in the form creation guide. You can also modify the values of these form fields using the UI or a programmable form-filling API.

Digital Signatures are a special case: A digitally signed SignatureFormField can’t be directly created by instantiating it. Please refer to the Digital Signatures on PSPDFKit for Web guide for more information.

Signature form fields and signature form elements require that your license includes either Electronic Signatures or Digital Signatures, or that your license was originally obtained in April 2021 or earlier. If none of these requirements are met, then other form elements will be shown, while signature elements will be omitted.