support-prerendering

Annotate the data property with [PersistentState] and fetch with the ??= pattern so the value is serialized during prerender and restored when the interactive runtime attaches. For complex scenarios, use PersistentComponentState with RegisterOnPersisting and TryTakeFromJson.

Set the render mode with prerender disabled, for example @rendermode @(new InteractiveServerRenderMode(prerender: false)) on a component definition, instance, or the Routes and HeadOutlet in App.razor. A parent's setting overrides children, so disabling on Routes applies app-wide.

Prerendering renders the component as static HTML first, then the interactive runtime re-renders it, so OnInitializedAsync executes once per phase. OnAfterRenderAsync only runs after the interactive render, never during prerender.

No, HttpContext is only available during the static prerender phase, not during the interactive lifetime. Mark pages needing cookies or request headers with [ExcludeFromInteractiveRouting] so they render via static SSR with full HttpContext access.

Components in the .Client project prerender on the server, where services registered only in the client Program.cs are unavailable. Register a matching server-side service, make the dependency optional, define a shared abstraction, or disable prerendering for that component.

Avoid disabling prerendering as a first resort because it hurts perceived load time and SEO. Prefer [PersistentState] to preserve data across the handoff, and only disable prerendering when a component depends on browser APIs immediately.