PDF Web Viewer Updates & Release Notes

Added

• Viewer users can fill in PDF form fields, toggle checkboxes and radio buttons, type into text boxes, and select options from combo boxes and list boxes. The PDF Web SDK exposes these form fields through the Forms namespace with CheckBoxWidget, RadioButtonWidget, TextBoxWidget, ComboBoxWidget, and ListBoxWidget classes.
• Developers can configure automatic navigation to a PDF’s initial destination using the useInitialDestination option. Set this option in ViewerConfig during initialization or pass it to Document.open(). When enabled, the viewer navigates to the PDF’s initial destination (if defined) when it opens.
• The hidePasswordDialogCancelButton option in ViewerConfig lets developers hide the cancel button in the password dialog. As a result, users must enter a password to proceed.
• New localization methods on PdfToolsViewer enable runtime language management:
  • addLanguage(): adds a new language at runtime.
  • customizeTranslations(): overrides specific translation strings.
  • getAvailableLocales(): lists all available locales.
  • getLocale(): returns the current locale.
  • setLocale(): switches the active locale (supports 'auto' for browser detection).
• The npm package includes third-party open-source license texts in the licenses/ directory. See licenses/MANIFEST.txt for the full list of components.

Changed

• The hideComponents(), showComponents(), and overrideButtonBehavior() methods accept component names instead of path-based references. A type alias provides strict typing for all valid component names.
• The file upload control is disabled while a document is loading, preventing users from uploading another file during the process.
• The viewer preserves the zoom level, fit mode, and page layout when opening a new document.
• The note annotation dialog has an improved layout and full keyboard accessibility.
• The password dialog has an improved layout and full keyboard accessibility.
• The print dialog dots per inch (DPI) selector displays a tooltip explaining each DPI value on hover.

Breaking changes

Localization configuration renamed

The customLocalisationFile configuration option is replaced by customTranslations in ViewerConfig, letting developers provide translation overrides directly in code instead of loading external files. The lang property is replaced by locale, which supports built-in and custom locales, as well as automatic browser detection.

Migration:
Replace customLocalisationFile: 'path/to/file.json' with customTranslations: { en: { key: 'value' } }. Replace lang: 'en' with locale: 'en'.

AnnotationType enum values renumbered

The AnnotationType enum values have shifted to accommodate form widget members (CheckBox 19, RadioButton 20, TextBox 21, ListBox 22, ComboBox 23). Affected values: Screen 19→24, PrinterMark 20→25, TrapNet 21→26, Watermark 22→27, Redact 23→28, 3D 24→29.

Migration:
Use the named enum members (AnnotationType.Redact) instead of raw integer values.

Fixed

• Before this update, printing on mobile devices failed silently or produced blank output when triggered from the print dialog. With this update, the print flow correctly renders document content on iOS and Android devices.
• Before this update, embedding the viewer in CSS flex or grid containers caused layout overflow and scrollbar issues. As a consequence, the viewer did not size correctly within modern CSS layouts. With this update, the viewer respects container constraints. As a result, the viewer displays correctly in flex and grid containers.
• Before this update, running multiple viewer instances on the same page caused style conflicts and rendering errors. With this update, viewer instances are properly isolated. As a result, multiple viewers can run simultaneously on the same page.

Added

• The Annotation class supports storing custom data through the privateData property of type string. The property persists across save and load cycles, letting applications attach domain-specific metadata to each annotation.
• The Document API emits a pageRendered event when a page finishes rendering. The event payload is the rendered page number.

Changed

• The addAnnotation(), deleteAnnotation(), and updateAnnotation() methods on viewer.document accept either a single annotation or an array of annotations, supporting batch operations with a single call.
• The viewer.document.getPage() method returns a Page synchronously instead of a Promise. Update existing code to call viewer.document.getPage(pageNumber) directly, without await.

Fixed

• Before this update, setting ViewerConfig.devicePixelRatio caused the viewer to crash at browser zoom levels other than 100% because the calculated canvas dimensions didn’t match the rendered buffer. As a consequence, viewer instances that configured devicePixelRatio failed whenever users zoomed the browser. With this update, the viewer derives the effective device pixel ratio from the rendered buffer size. As a result, the viewer renders correctly at any browser zoom level.
• Before this update, text selection under certain circumstances ended one character before the end of the selected word. As a consequence, viewer users couldn’t include the final character when selecting a complete word. With this update, the text-selection logic includes the last glyph in the range. As a result, viewer users can select complete words.

Added

• Viewer users can create ink annotations (freehand drawings) on PDF documents, customize the stroke color, opacity, and line width, erase parts of the drawing, and edit annotations by moving, resizing, locking, or deleting them.
• Developers can set the annotation author using the user option in ViewerConfig during initialization, or the setUser() method on PdfToolsViewer at runtime. The getUser() method returns the configured user. The viewer applies this value when creating or editing annotations.
• The document.addAnnotation() method lets developers add annotations to PDF documents programmatically.
• Developers can configure the device pixel ratio (DPR) using the devicePixelRatio option in ViewerConfig to balance rendering sharpness and performance. Higher values increase sharpness, while lower values improve performance.
• Viewer users can navigate sidebar panels with the keyboard, move the focus between elements using the Tab key, navigate menu items with the arrow keys, and activate buttons with the Enter or Spacebar keys.

Changed

• The viewer.initialize() method throws an error when called on an already initialized viewer instance. Developers must dispose of the existing instance before reinitializing. Use viewer.addEventListener("PdfTools.viewer.initialized") to detect when initialization completes.
• Updated embedded fonts for improved license compliance.

Fixed

• Before this update, the lock/unlock button in the sticky note modal didn’t reflect the current annotation state. With this update, the button stays synchronized with the contextual menu.
• Before this update, viewer users couldn’t create redaction annotations on touchscreen devices. This has been resolved.
• Image upload validates file types and prevents viewer users from selecting unsupported formats.
• The thumbnail panel displays equal left and right margins.
• Redaction annotations are included when saving documents as FDF.

Added

• Viewer users can create rectangle and ellipse shape annotations. Users can customize the border color, fill color, and border width, and edit these annotations by moving, resizing, locking, or deleting them.
• Toolbar buttons display dark-themed tooltips on hover.
• PDF Viewer SDK supports FDF (Forms Data Format). Save or download documents as FDF by setting the
  saveAsFdf
  option to
  true
  :
  viewer.document.save({saveAsFdf:
  true
  }) ;
• A loading spinner and progress bar provide visual feedback while the viewer uploads and opens documents.
• Viewer users can set the input document parameter when initializing the viewer to skip the document upload screen:
  viewer.initialize({inputDocument: {uri:
  'url_to_a_file'
  } ,
  ...}) ;
  viewer.initialize({inputDocument: {data: file} ,
  ...}) ;

Changed

• Redesigned the thumbnails panel. The active page displays with a blue highlight.
• Toolbar dropdown components (zoom, fit mode, page layout, and pagination) close automatically when users click outside or open another dropdown.
• The pagination component supports page number input, letting users navigate to a specific page directly.
• Updated icons throughout the viewer, including the file open icon and line ending icons in the annotation popover.
• Redesigned the document upload screen.
• Rewrote the document opening flow, removing code duplication and memory leaks.

Fixed

• Toolbar icons no longer shift position when navigating to pages with two or more digits.
• Dropdown panels (zoom, fit mode, layout, and annotation popovers) no longer overlap. Opening one panel closes any other open panel.
• Opening the search or thumbnails panel no longer deactivates the active plugin.
• The sticky notes popover closes immediately when activating stamp or redaction plugins, rather than waiting for the sidebar to open.
• Before this update, the app layout used a deprecated layout system. As a result, page margins were inconsistent on mobile and tablet devices. With this update, the app layout uses a consistent margin system across desktop, mobile, and tablet devices.

Added

• Viewer users can create redaction annotations by selecting text, drawing rectangles on the document, or redacting the current page or a specified range of pages. A dedicated Redact panel displays all redaction annotations, allowing users to lock them to prevent accidental edits or delete them.
• Viewer users can download a redacted version of the document using Apply Redactions button in the Redact panel. Annotations are not included in the downloaded file.

Changed

• Zoom level change events are debounced, which enhances performance when users rapidly zoom in and out of documents.
• Refactored the PDF Viewer SDK API. As a result, the API has reduced the number of parameters and configuration options, delivering the same functionality with greater simplicity and usability.
• Improved and faster build process, valid source maps, and reliable ECMAScript Modules (ESM) and Universal Module Definition (UMD) bundles.

Fixed

• Replaced delete and lock icons across all context menus with consistently sized icons, making actions easier to identify.

Added

• Users can add text annotations (free-text notes) to PDFs, supporting rich text formatting with options for font family, font size, text color, alignment, and styles such as bold, italic, and underline. Text annotations can be edited inline, moved by dragging, or deleted.
• Users can now add image annotations to PDFs by selecting and placing an image on the document. Existing image annotations can be moved, resized, deleted, or locked.
• With this release, the PDF Web Viewer enables developers to create custom plugins using a dedicated plugin API. Developers can register, activate, and deactivate plugins, create layers for drawing on the document view, and add buttons to control plugin state.
• The PDF Web SDK exposes accessibility events and keyboard interactions through the TextSelectionPlugin. The cursorPositionChanged event enables tracking of cursor position changes. The keyDown event exposes keyboard interactions. In text selection mode, users can click on text to display a cursor. They can move the text using the arrow keys. Users can select text with Shift + Arrow, navigate word by word with Ctrl or Cmd + Arrow, and select word by word with Shift + Ctrl or Cmd + Arrow.
• Added support for redaction annotations as a TextMarkupType in the PDF Web SDK. As a result, developers can implement redaction annotation creation in their applications.

Changed

• The textSelectionChanged event now provides additional geometry data. This includes selection quadrilaterals with page numbers, start and end page numbers, and the selected text content. The following method was changed:
  The following methods changed:
  textSelectionChanged()
  From:
  textSelectionChanged: (selectedText: string) => void
  To:
  textSelectionChanged: (textSelectionData: TextSelection) => void

• The PDF Web Viewer enhanced web components for improved accessibility, introducing updated button, menu, dropdown, and toolbar components. All components are now fully keyboard accessible and screen reader compatible.
  The following methods changed:
  hideComponents()
  From:
  hideComponents: (components: HideableComponentConfigName[]) => void
  To:
  hideComponents: (paths: string[] | string[][]) => void
  showComponents()
  From:
  showComponents: (components: HideableComponentConfigName[]) => void
  To:
  showComponents: (paths: string[] | string[][]) => void
  overrideButtonBehavior()
  From:
  overrideButtonBehavior: (buttonName: string, eventName: string, callback: () => void ) => void
  To:
  overrideButtonBehavior: (path: string | string[], eventName: OverridableButtonEventType, callback: () => void) => void;