Asp.Net Document Viewer

Published on 06 Sep 2025

Tags: Asp.Net

In this blog post we will discuss about how UnoViewer can help you view documents online in your Asp.Net web application. It can be a Webforms site, .Net Core MVC, Docker (Linux), Blazor or other single page application (SPA) framework like Angular, React or Vue.

How does UnoViewer work

Asp.Net Document Viewer
Following summarizes UnoViewer's functionality.

  • User uploads a Microsoft Office format (DOC, XLS, PPT) or Acrobat PDF file.
  • You can also view existing document already available on your server.
  • UnoViewer can take file path as an input or you can load the file from memory stream.
  • Optionally the Microsoft Office document is converted to PDF prior to viewing.
  • This document instance is stored in server's memory.
  • As the viewer is browsing the document, pages get requested on-demand (lazy loading) from the server.
  • The pages are rendered back to client browser in image / png format.

Native .NET C# based viewer

UnoViewer does not require you to install anything on the server or client. It supports Word, Excel, PowerPoint and Acrobat PDF out of the box. More file formats will be added in the future releases.

  • No software, interop, plug-in required.
  • We recommended installing all the necessary fonts on the web server.
  • UnoViewer even works on a shared hosting environment, virtual private server (VPS). Dedicated server is suggested for high traffic websites.
  • There is a time-out property of the viewer. After specified time of user inactivity the document instance will get disposed automatically.

Asp.Net Document Viewer Github

UnoViewer samples are actively maintained and available for free download from our official Github repository. Following are the available project / solution types.

  • Webforms .NET Framework 4.8.
  • .NET Core / .NET 6.0 MVC.
  • Blazor (Server).
  • Docker (Linux).
All of the above code is in C# (Csharp) however you can easily implement it using VB.NET too. Using Docker containers, it is also possible to use it from different programming platforms like Php, JAVA etc.

UnoViewer Documentation

A detailed documentation about our versatile Asp.Net online file viewer is available.

View Word Documents In Asp.Net