See v4 migration guide for information on the main breaking changes.

• The lineCount property is now a property on the CalloutCreateTool prototype instead of a property on the constructor.
• The getMarkupOff, setMarkupOff, toggleAnnotations, getUseFilter, setUseFilter and filterAnnotations functions on AnnotationManager have been removed. You can achieve the same functionality using AnnotationManager's hideAnnotations and showAnnotations functions.

• The beta UI is now the default viewer. The legacy UI can be enabled by passing ui: 'legacy' in the WebViewer constructor.
• jQuery is no longer required to be loaded as a dependency along with webviewer.min.js.
• Added support for viewing annotation appearances on all markup annotations and on push button widgets. AnnotationManager's drawAnnotations function is now asynchronous and returns a promise to accommodate this.
• Many structural changes to the download package. The lib folder has been changed so that the UI and core files are in separate folders. The samples have also been revamped.
• Incremental loading of annotations is now supported to more quickly render and display annotations when jumping to a random page.
• Allow annotations to be dragged outside of the page boundaries using a new flag ALLOW_ANNOTS_OUTSIDE_PAGE on the base tool object.
• The default FreeText font has been changed from Verdana to Helvetica.
• Added the MaintainAspectRatio property to annotations. If true then the annotation will only have control points on the corners and the aspect ratio will be maintained when resizing.
• Added a getAnnotationsLoadedPromise function on DocumentViewer that can be used instead of the annotationsLoaded event if preferred.
• Added setAnnotationDisplayAuthorMap and getDisplayAuthor functions on AnnotationManager to allow easy mapping between annotation author ids and the name that is displayed in the UI.
• Added displayPageLocation function on DocumentViewer to jump to a specific location on a page.
• Updated WinRT sample to work with VS2017.

• Fixed issue with caching too much page text data when calling loadPageText.
• Fixed issue where annotations would be unnecessarily rerendered when the visible pages changed.
• Fixed issue with margins not being removed when printing in Edge.
• Fixed issue with loading documents that have a query or hash parameter in the path.