Overview of Blazor PDF Viewer Component

12 Feb 20265 minutes to read

The Blazor SfPdfViewer component enables viewing, annotating, printing, and downloading PDF files in Blazor applications without requiring a separate server-side PDF service. It provides fast, responsive rendering and is straightforward to integrate into both Blazor Server and Blazor WebAssembly (WASM) applications.

SfPdfViewer delivers the core capabilities of the Blazor PDF Viewer component while adding client-side rendering, reduced server round-trips, and a unified cross-platform package. Key advantages are summarized below.

Performance Improvements

Rendering, scrolling, zooming, panning, and printing have been optimized for faster, smoother interaction and reduced latency.

Elimination of Service Dependency

The classic PDF Viewer required a separate service URL to load documents. SfPdfViewer can load documents directly in the browser (see the Blazor WebAssembly), enabling offline scenarios and reducing network overhead. Server-side hosting remains supported when required.

Common Package

Previously, separate NuGet packages were required for each operating system: Windows, Linux, and OSX. The Syncfusion.Blazor.SfPdfViewer package now provides a single, cross-platform distribution for all supported environments.

Reduced Server Calls

In the classic viewer, many C# service calls were required to retrieve page text, hyperlinks, and page images. SfPdfViewer performs these operations client-side where possible, decreasing round trips and improving responsiveness.

Some of the key features are listed below

• Accurate, reliable rendering of PDF pages.
• Easy page navigation with:
  • Thumbnail page view
  • Bookmark panel
  • Hyperlink navigation
  • Table of contents navigation
• Core interactions:
  • Zooming and panning
  • Text searching
  • Text selection and copy
• Print PDF files.
• Annotate PDFs with:
  • Highlight, underline, and strikethrough text markup
  • Shape annotations: rectangle, circle, polygon, line, and arrow
  • Stamp annotations: built-in and custom stamps
  • Measurement annotations
  • Free text annotations
  • Redaction annotations
  • Comments and sticky notes
• Form filling
• Form designer
• Handwritten signature

Supported Features: Desktop vs Mobile

The following table summarizes feature support on desktop and mobile devices.

Feature	Desktop	Mobile devices
Keyboard interaction	Yes	No
Open file from a different origin	Yes	Yes
Save a file to a different origin	Yes	Yes
Toolbar	Yes	No
Mobile toolbar	No	Yes
Navigation toolbar	Yes	No
Page navigation	Yes	No
Magnification	Yes	Yes
Text search	Yes	Yes
Text selection	Yes	No
Pan mode	Yes	Yes
Handwritten signature	Yes	Yes
Annotation rendering	Yes	Yes
Annotation interaction	Yes	Yes
Annotation property editing	Yes	No
Add annotation through touch	Yes	No
Import/export annotation	Yes	Yes
Form fields rendering	Yes	Yes
Form Designer	Yes	Yes
Modern Navigation Panel	Yes	Yes
Organize Pages	Yes	Yes

NOTE

Enable desktop mode on mobile devices using the EnableDesktopMode property to display the toolbar as on desktop.

NOTE

The SfPdfViewer component is available for both Blazor Server and Blazor WebAssembly applications. Use the SfPdfViewer component from the Syncfusion.Blazor.SfPdfViewer NuGet package; server-side processing through a web service is not required to render PDF files in client scenarios. For platform-specific server packages, see the NuGet listings for Windows, Linux, and macOS.

NOTE

See the Blazor SfPdfViewer feature tour for a concise overview of capabilities and the Blazor SfPdfViewer demo to explore core features interactively.