# Convert Blazor Server To Webapp

Guides conversion of a pre-.NET 8 Blazor Server app into a .NET 8+ Blazor Web App.

- Repository: https://github.com/dotnet/skills (5787 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add dotnet/skills --skill convert-blazor-server-to-webapp -g -a claude-code -y`
Codex: `npx skills add dotnet/skills --skill convert-blazor-server-to-webapp -g -a codex -y`
Cursor: `npx skills add dotnet/skills --skill convert-blazor-server-to-webapp -g -a cursor -y`
Gemini CLI: `npx skills add dotnet/skills --skill convert-blazor-server-to-webapp -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add dotnet/skills`

## Description

Guides conversion of a pre-.NET 8 Blazor Server app into a .NET 8+ Blazor Web App. USE FOR: migrating apps that use AddServerSideBlazor and MapBlazorHub to the AddRazorComponents/MapRazorComponents model, converting _Host.cshtml to an App.razor root component, replacing blazor.server.js with blazor.web.js, migrating CascadingAuthenticationState to a service, adopting new Blazor Web App features like enhanced navigation and streaming rendering. DO NOT USE FOR: apps that are already Blazor Web Apps (already use AddRazorComponents and MapRazorComponents), Blazor WebAssembly or hosted Blazor WebAssembly apps (different migration path), apps that should stay on the Blazor Server hosting model without converting, or apps still targeting .NET Framework.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Convert Blazor Server App to Blazor Web App

This skill helps an agent convert a pre-.NET 8 Blazor Server app into a .NET 8+ Blazor Web App. The old hosting model uses `AddServerSideBlazor`/`MapBlazorHub` with a `_Host.cshtml` Razor Page as the entry point. The new Blazor Web App model uses `AddRazorComponents`/`MapRazorComponents` with an `App.razor` root component, enabling per-component render modes, enhanced navigation, streaming rendering, and other .NET 8+ features. The converted app uses `InteractiveServer` render mode to preserve existing interactive behavior.

## When to Use

- Migrating a Blazor Server app from .NET 6 or .NET 7 to .NET 8+
- App currently uses `AddServerSideBlazor()` and `MapBlazorHub()` in `Program.cs` (or `Startup.cs`)
- App uses `Pages/_Host.cshtml` (or `_Host.razor`) as the host page with Component Tag Helpers
- Want to adopt new Blazor Web App features while keeping interactive server rendering

## When Not to Use

- **The app already uses `AddRazorComponents` and `MapRazorComponents`.** It is already a Blazor Web App, no conversion is needed. Stop here and tell the user the app is already using the Blazor Web App model.
- Blazor WebAssembly or hosted Blazor WebAssembly app, these have a different migration path
- The app should stay on the legacy Blazor Server hosting model (just update TFM and packages)
- The app targets .NET Framework, it must be migrated to .NET first

## Inputs

| Input | Required | Description |
|-------|----------|-------------|
| Blazor Server project | Yes | The `.csproj` and source files of the Blazor Server app |
| Target framework | Yes | .NET 8 or later (e.g., `net8.0`, `net9.0`, `net10.0`) |
| `Program.cs` or `Startup.cs` | Yes | The app's service and middleware configuration |
| `_Host.cshtml` location | Recommended | Usually `Pages/_Host.cshtml`; may be `_Host.razor` in some projects |

## Workflow

The rest: https://github.com/dotnet/skills/blob/HEAD/plugins/dotnet-aspnetcore/skills/convert-blazor-server-to-webapp/SKILL.md