---
title: "Store PDF form data on iOS"
canonical_url: "https://www.nutrient.io/guides/ios/forms/introduction-to-forms/data-formats/"
md_url: "https://www.nutrient.io/guides/ios/forms/introduction-to-forms/data-formats.md"
last_updated: "2026-06-08T17:11:05.541Z"
description: "Learn how to efficiently store and manage PDF form data on iOS using interactive widget annotations."
---

# Store PDF form data on iOS

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. See our [annotation data formats](https://www.nutrient.io/guides/ios/annotations/introduction-to-annotations/data-formats.md) guide to learn more.
---

## Related pages

- [Understanding PDF forms and their benefits](/guides/ios/forms/introduction-to-forms.md)
- [Supported PDF form fields on iOS](/guides/ios/forms/introduction-to-forms/form-fields.md)