How do I get the page referrer in Blazor?

Create a JavaScript function as a separate file in your application (~/wwwroot/interop.js).

function getPageReferrer()
  {
     return document.referrer;
 }

Add the script reference in the ~/wwwroot/index.html file of the Blazor WebAssembly application.

 <script src="interop.js"></script>

Invoke the JavaScript function using the IJSRuntime service in a Razor page.

 @page "/"
 @inject IJSRuntime JSRuntime
 @code { 
 protected override async Task OnInitializedAsync()
 {
	var pageReferrer = await JSRuntime.InvokeAsync<string>("getPageReferrer"); 
 }
 } 

View Sample in GitHub