--- title: "Comprehensive PDF annotation library for Flutter applications | Nutrient Flutter SDK" canonical_url: "https://www.nutrient.io/guides/flutter/annotations/" md_url: "https://www.nutrient.io/guides/flutter/annotations.md" last_updated: "2026-06-08T17:11:05.525Z" description: "Enhance your Flutter applications with our comprehensive PDF annotation library. Create, edit, and manage 17 types of annotations seamlessly with a customizable UI." --- # Comprehensive PDF annotation library for Flutter applications Nutrient Flutter SDK is a comprehensive library for creating, editing, and removing PDF annotations in your applications. It empowers developers with programmatic annotation management and features a customizable user interface (UI) for seamlessly handling 17 PDF annotation types, including highlights, text, ink, and shapes. With its powerful features and intuitive design, our Flutter PDF annotation library streamlines annotation workflows and improves the end user experience in your application. ## What are annotations? PDF pages are typically not designed for direct content editing. However, the PDF specification includes a robust set of objects known as annotations, which can be added to PDF pages without altering the original content. These annotations serve various purposes — from marking up text and highlighting content, to enabling interactive features such as form fields. This flexibility makes annotations a powerful tool for enhancing PDF functionality. [Learn more](https://www.nutrient.io/guides/flutter/annotations/introduction-to-annotations/what-are-annotations.md) ## Working with annotations --- **Supported annotation types** Explore the 17 annotation types supported by Nutrient, including highlights, text, and ink [Read more](https://www.nutrient.io/guides/flutter/annotations/introduction-to-annotations/annotation-types.md) --- **Bounding boxes** Learn how to access and modify the bounding box of an annotation for precise placement and customization [Read more](https://www.nutrient.io/guides/flutter/annotations/introduction-to-annotations/bounding-boxes.md) --- **Flatten annotations** Discover how to flatten annotations to merge them permanently into the PDF content [Read more](https://www.nutrient.io/guides/flutter/annotations/flatten.md) ## Saving and storing annotations --- **Embed annotations into a PDF** Learn how to embed annotations directly into a PDF document for seamless integration [Read more](https://www.nutrient.io/guides/flutter/annotations/save/embed-into-pdf.md) --- **Manually saving annotations** Discover how to trigger a manual save operation for annotations in your PDF [Read more](https://www.nutrient.io/guides/flutter/annotations/save/manual-save.md) --- **Annotation auto save** Understand how annotations are automatically saved to ensure data persistence [Read more](https://www.nutrient.io/guides/flutter/annotations/save/auto-save.md) --- **Annotation saving permissions** Explore the conditions and permissions required for saving annotations within a PDF [Read more](https://www.nutrient.io/guides/flutter/annotations/save/saving-permissions.md) ## Import and export --- **Import and export XFDF** Learn how to seamlessly import and export XFDF annotations to and from a PDF document [Read more](https://www.nutrient.io/guides/flutter/annotations/import-and-export/xfdf.md) --- **Import and export Instant JSON** Discover how to import and export Instant JSON annotations to and from a PDF for efficient annotation management [Read more](https://www.nutrient.io/guides/flutter/annotations/import-and-export/instant-json.md) ## Create, edit, or remove annotations --- **Programmatic creation, editing, and removal** Learn how to programmatically create, edit, and remove annotations for precise control over PDF content [Read more](https://www.nutrient.io/guides/flutter/annotations/create-edit-and-remove/programmatic.md) --- **Annotation events and notifications** Learn how to handle annotation events and notifications in PDF viewer applications using Nutrient Flutter SDK [Read more](https://www.nutrient.io/guides/flutter/events-and-notifications/annotation.md) --- **Disable annotation editing** Find out how to disable editing for specific annotations or annotation types to maintain document integrity [Read more](https://www.nutrient.io/guides/flutter/annotations/create-edit-and-remove/disable-editing.md) --- **Annotation author name** Configure the author name for annotations to personalize and track who made each change [Read more](https://www.nutrient.io/guides/flutter/annotations/create-edit-and-remove/author-name.md) --- **Annotate on an image** Learn how to annotate on images such as PNG, JPG, or TIFF, extending annotation capabilities beyond PDFs [Read more](https://www.nutrient.io/guides/flutter/annotations/annotate-on-images/create-edit-and-remove.md) ## Image annotation specification --- **Image document specification** Learn how Nutrient enables annotations on PNG, JPG, and TIFF images, storing them in the XMP format for seamless integration and preservation of image quality [Read more](https://www.nutrient.io/guides/flutter/annotations/annotate-on-images/specification.md) ## FAQ: Annotating with Nutrient Flutter SDK #### What annotation types are supported by Nutrient Flutter SDK? Nutrient Flutter SDK supports 17 annotation types, including highlights, text, ink, and shapes, giving developers a wide range of options for annotating PDFs. #### Can annotations be created and edited programmatically? Yes, you can programmatically create, edit, and remove annotations using Nutrient Flutter SDK, offering flexibility for developers. #### How are annotations saved in Nutrient Flutter SDK? Annotations can be saved manually or automatically, and they can be stored in XFDF or Instant JSON formats for efficient management and persistence. #### Can annotations be added to image files? Yes, Nutrient Flutter SDK allows you to annotate image formats like PNG, JPG, and TIFF by embedding annotations in the XMP format while preserving the image quality. #### Is the annotation UI customizable in Nutrient Flutter SDK? Yes, Nutrient Flutter SDK provides a fully customizable annotation UI, allowing you to tailor the interface by hiding annotation buttons and adjusting the design to match your app’s branding. **Call to Action** Start your free trial for unlimited access and expert support. [Learn More](https://www.nutrient.io/sdk/flutter/getting-started.md) --- ## Related pages - [Flatten annotations in Flutter](/guides/flutter/annotations/flatten.md) ## Pages in this section - [Set the annotation author in Flutter](/guides/flutter/annotations/create-edit-and-remove/author-name.md) - [Define annotation behavior with flags in Flutter](/guides/flutter/annotations/create-edit-and-remove/annotation-flags.md) - [Disable annotation editing in Flutter](/guides/flutter/annotations/create-edit-and-remove/disable-editing.md) - [Programmatically manage PDF annotations in Flutter](/guides/flutter/annotations/create-edit-and-remove/programmatic.md) - [Update PDF annotation properties in Flutter](/guides/flutter/annotations/create-edit-and-remove/update-properties.md) - [Programmatically annotate images with Flutter SDK](/guides/flutter/annotations/annotate-on-images/create-edit-and-remove.md) - [Image annotation specifications for PNG and JPEG](/guides/flutter/annotations/annotate-on-images/specification.md) - [Supported annotation types in Flutter](/guides/flutter/annotations/introduction-to-annotations/annotation-types.md) - [Retrieve or set the annotation bounding box in Flutter](/guides/flutter/annotations/introduction-to-annotations/bounding-boxes.md) - [What are PDF annotations?](/guides/flutter/annotations/introduction-to-annotations/what-are-annotations.md) - [Import and export PDF annotations from Instant JSON in Flutter](/guides/flutter/annotations/import-and-export/instant-json.md) - [Import and export PDF annotations from XFDF files in Flutter](/guides/flutter/annotations/import-and-export/xfdf.md) - [Embed annotations in a PDF file on Flutter](/guides/flutter/annotations/save/embed-into-pdf.md) - [Customize annotation saving permissions in Flutter](/guides/flutter/annotations/save/saving-permissions.md) - [Auto save annotations in Flutter](/guides/flutter/annotations/save/auto-save.md) - [Manually save annotations in Flutter](/guides/flutter/annotations/save/manual-save.md)