PDF form elements and data formats
Under the hood, PDF form elements are a type of PDF annotation called “widget” annotations. They’re used to implement interactive form elements, such as buttons, checkboxes, combo boxes, and more.
Widgets that can hold a value — like checkboxes, combo boxes, and text fields — store their data separately in an entity called a form field. All data formats Nutrient supports for encoding annotations are designed to also encode the values of form fields. Refer to the annotation data formats guide to learn more.
When to use each format
Use this table to choose the form data format based on your workflow requirements.
| Format | Use when |
|---|---|
| Instant JSON | You need the default internal persistence/sync format for browser form workflows. |
| XFDF | You need interoperability with external PDF tools. |
| Document Engine with Instant synchronization | You need collaborative, multiuser form workflows across sessions/devices. |
For an end-to-end authoring workflow, refer to the building a browser form template builder guide.