---
title: "Supported PDF annotation types in iOS viewer | Nutrient SDK"
canonical_url: "https://www.nutrient.io/guides/ios/annotations/introduction-to-annotations/annotation-types/"
md_url: "https://www.nutrient.io/guides/ios/annotations/introduction-to-annotations/annotation-types.md"
last_updated: "2026-06-19T09:21:00.273Z"
description: "Supported PDF annotation types in iOS viewer | guide for Nutrient iOS SDK with detailed instructions and code examples."
---

# Supported PDF annotation types on iOS

Nutrient iOS SDK supports all common annotation types:

- [Link](https://www.nutrient.io/api/ios/documentation/pspdfkit/linkannotation)

- [Highlight](https://www.nutrient.io/api/ios/documentation/pspdfkit/highlightannotation), [Underline](https://www.nutrient.io/api/ios/documentation/pspdfkit/underlineannotation), [Strikeout](https://www.nutrient.io/api/ios/documentation/pspdfkit/strikeoutannotation), [Squiggly](https://www.nutrient.io/api/ios/documentation/pspdfkit/squigglyannotation)

- [Free Text](https://www.nutrient.io/api/ios/documentation/pspdfkit/freetextannotation)

- [Ink](https://www.nutrient.io/api/ios/documentation/pspdfkit/inkannotation)

- [Square](https://www.nutrient.io/api/ios/documentation/pspdfkit/squareannotation), [Circle](https://www.nutrient.io/api/ios/documentation/pspdfkit/circleannotation), [Line](https://www.nutrient.io/api/ios/documentation/pspdfkit/lineannotation), [Polyline](https://www.nutrient.io/api/ios/documentation/pspdfkit/polylineannotation), [Polygon](https://www.nutrient.io/api/ios/documentation/pspdfkit/polygonannotation)

- [Note](https://www.nutrient.io/api/ios/documentation/pspdfkit/noteannotation)

- [Sound](https://www.nutrient.io/api/ios/documentation/pspdfkit/soundannotation)

- [File](https://www.nutrient.io/api/ios/documentation/pspdfkit/fileannotation)

- [Widget](https://www.nutrient.io/api/ios/documentation/pspdfkit/widgetannotation) (requires the [Forms component](https://www.nutrient.io/guides/ios/forms.md))

- [Image/Stamp](https://www.nutrient.io/api/ios/documentation/pspdfkit/stampannotation)

- [Rich Media/Video](https://www.nutrient.io/api/ios/documentation/pspdfkit/richmediaannotation), [Screen](https://www.nutrient.io/api/ios/documentation/pspdfkit/screenannotation)

- [Caret](https://www.nutrient.io/api/ios/documentation/pspdfkit/caretannotation)

- [Redaction](https://www.nutrient.io/api/ios/documentation/pspdfkit/redactionannotation) (requires the [Redaction component](https://www.nutrient.io/guides/ios/redaction.md))

These are standard annotations (as defined in the PDF Reference) that can be read and written by many apps, such as Adobe Acrobat and Apple Preview. Most of these annotation types can also be written back, except for rich media/video, file, and widget annotations. For more details, refer to the [What Are Annotations?](https://www.nutrient.io/guides/ios/annotations/introduction-to-annotations/what-are-annotations.md) guide.

## Signature annotations

Ink and image annotations may be used as signatures. See [adding an electronic signature](https://www.nutrient.io/guides/ios/signatures/adding-an-electronic-signature.md) to learn more. Using the signature tool requires the [Electronic Signatures component](https://www.nutrient.io/guides/ios/signatures/adding-an-electronic-signature.md). For licenses originally obtained in April 2021 or earlier, limited signing functionality is available with just the Annotations component.
---

> Part of [PDF annotation library for iOS](/guides/ios/annotations/introduction-to-annotations.md)

## Related pages

- [What are PDF annotations?](/guides/ios/annotations/introduction-to-annotations/what-are-annotations.md)
- [Compare XFDF and Instant JSON for PDF annotations](/guides/ios/annotations/introduction-to-annotations/data-formats.md)