Skip to content
Demo on how to run dynamically in client or server side mode
Branch: master
Clone or download
Pull request Compare This branch is 4 commits ahead, 3 commits behind Suchiman:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.


Demo on how to dynamically switch from client to server side mode by appending ?mode=server to the url.


This commit summarizes the necessary changes.

  1. You need to change the Startup class of the hosting ASP.NET Core application to set the app up as a Server Side Blazor app. This doesn't have adverse effects on Client Side Blazor but enables the Server Side services. For that you need to have services.AddServerSideBlazor<Client.Startup>(); in ConfigureServices and app.UseServerSideBlazor<Client.Startup>(); in Configure
  2. We can now serve Client Side and Server Side apps but we need to polyfil the HttpClient that is provided in DI in Client Side by default. Server Side doesn't register it by default so we detect this and then register an HttpClient in DI that behaves similiar for compatibility
    // Server Side Blazor doesn't register HttpClient by default
    if (!services.Any(x => x.ServiceType == typeof(HttpClient)))
    	// Setup HttpClient for server side in a client side compatible fashion
    	services.AddScoped<HttpClient>(s =>
    		// Creating the URI helper needs to wait until the JS Runtime is initialized, so defer it.
    		var uriHelper = s.GetRequiredService<IUriHelper>();
    		return new HttpClient
    			BaseAddress = new Uri(uriHelper.GetBaseUri())
  3. At this point, the only difference is which blazor JS file we load in the browser. This can be either achieved by serving a different index.html (for which i couldn't see an easy way) or using a small piece of JS to decide which file to load
    <script id="blazorMode"></script>
    	document.getElementById("blazorMode").src ="mode=server") ? "_framework/blazor.server.js" : "_framework/blazor.webassembly.js";
You can’t perform that action at this time.