GroupDoc.Viewer offline


Possibility to view the documents in html5 offline mode



Thank you for your interest in GroupDocs.Viewer for .NET. Can you please clarify your request? If we understand you correctly, you ask about ability to display documents in the GroupDocs.Viewer when the client has no connection with the web-server. Correct us if we are wrong.

The only way for doing this is to use GroupDocs.Viewer WinForms control, which should be used in the WinForms desktop applications. But it that case it is not a web-application, it is a desktop application, that works locally and doesn’t connect to the web-server at all.

Unfortunately it is not possible to display documents in the HTML5 offline mode in the browser, because GroupDocs.Viewer is a client-server application. When you open a document, GroupDocs.Viewer on the server-side converts it to the HTML-compatible form, and then end-user in a browser obtains this document as a simple HTML page with images, text, scripts, CSS and so on. When web-server is unavailable, there is no way to display the new documents because displaying assumes converting to the HTML form on the server-side.

Maybe we understood your question incorrect, in that case please correct us.


Possibility to view the documents in html5 offline mode


Thanks you very much for your answer.
In html5 application, is there a way to store locally the converted html’s documents, and then to show this html parts documents when the users are offline ?

Server .net --> html docs --> users (in html5 javascript application)

(html js application with stored locally html converted docs)

Thanks you very much



Right now GroupDocs.Viewer for .NET doesn’t support such offline mode. When you open the document, only requested pages are streamed to the client-side on demand, it is done in order to improve performance of the client-side. When you scroll down the document, new document pages are smoothly streaming and seamlessly integrating into the web-page.

But ability to download the whole document at a time (in one request to the server-side), with possibility to display all its pages without sending additional requests to the server, is already planned. Support for offline viewing is already present in our roadmap and will be implemented in the future.

When this feature will be ready, end-user will be able to open a document in the browser using the GroupDocs.Viewer, and then turn off his internet-connection (or shut down of the web-server, what is the same thing in this particular scenario); the whole document still will be available for the viewing in the browser.




After discussion with developers we want to notify you that GroupDocs.Viewer already contains some sort of offline viewing. There is a method “PreloadPagesCount” in the GroupDocs.Viewer widget, and when specifying a “.PreloadPagesCount(null, true)”, then all document pages will be downloaded to the browser immediately, without need to scroll down all the document. And then, when the internet connection will be shut down, end-user still is able to browse all document pages. So this option should be considered as an offline viewing. But, if user will perform a page reload (refresh) in the browser, and the server will be offline in that moment, this will not work.

If you will have more questions please feel free to contact us.