Disclaimer: This post references features from the .NET 10 preview at time of writing. Some APIs and behaviors may evolve before general availability (GA). Always verify implementation details against the latest Microsoft docs.
Introduction: What’s New in Blazor .NET 10?
Blazor brings full-stack web development to C# and .NET, empowering developers to minimize the complexity of JavaScript for most core application logic (though JS interop is still there when you need it). The .NET 10 release takes Blazor to the next level, with modern upgrades in security, diagnostics, performance, and developer experience.
Here’s what stands out—informed by real-world feedback and public Microsoft sources.
Passwordless Security: Passkey Support and Its Limits
.NET 10 preview brings built-in support for passwordless authentication (WebAuthn + passkeys), making logins more secure and user-friendly:
- Passkeys are phishing-resistant and work across devices.
- In default Blazor templates, user registration still requires a password; passkeys augment rather than fully replace passwords for now.
- For advanced WebAuthn scenarios (attestation/certification), a library like Fido2 may be needed.
Learn more from Andrew Lock’s deep dive and the official ASP.NET Core blog.
Diagnostics, Metrics & Observability: Measured Progress
.NET 10’s diagnostics improve troubleshooting with:
- Enhanced tracing for Blazor Server (OpenTelemetry integration).
- Easier performance profiling and trace collection for WebAssembly via
.nettracefiles. - Page navigation, UI event, and circuit-connection metrics (these depend on preview/GA status—see DarthPedro’s blog for the latest).
Be cautious: Many observability features are preview or evolving, so expect some APIs and dashboards to change.
Performance: Real Gains, Citable Stats
- Startup and load times are improved via compression, fingerprinting, and caching of Blazor scripts.
- WebAssembly payloads are smaller and load faster—startup improvements verified in benchmarks (DarthPedro’s .NET 10 post).
- Instead of fixed “20% faster” claims, measure gains in your own projects after upgrade.
Developer Experience: What’s New
- Hot reload is significantly faster in latest Visual Studio previews (though final performance may vary).
- Nested model validation for forms—just add
[Required],[EmailAddress], etc. at all object levels and callbuilder.Services.AddValidation(). - QuickGrid adds more customization (row classes, visibility toggles).
- JavaScript interop is smoother for advanced scenarios.
State Persistence & Circuit Management: Pragmatic Resilience
- State persistence lets you retain user/circuit state when browsers disconnect or go idle.
By default, persisted state is stored in memory and is “best effort.” For mission-critical resilience, configure external durable persistence or a hybrid cache (see this GitHub issue for discussion).
- “Pause” and “resume” APIs help optimize resources at scale, especially in enterprise scenarios.
Comparing Rendering Modes in .NET 10
| Mode | Pros & Best Use | .NET 10 Improvements |
|---|---|---|
| Server | Fast initial load, always connected | Enhanced state persistence |
| WebAssembly (WASM) | Rich, interactive UI, works offline | Smaller payloads, better diagnostics |
| Hybrid (Auto) | Mix of server + WASM, progressive loading | Better defaults, automatic best choice |
Cloud-Native Bonus: .NET Aspire 13
.NET 10 now integrates tightly with .NET Aspire 13 for orchestration, monitoring, and cloud deployments. Enterprise teams get a more seamless, production-ready development-to-deployment story.
Real-World and Enterprise Adoption
- Tyler Technologies’ MyRide app (2,500+ schools; 750k downloads) uses Blazor for web + native cross-platform delivery.
- LKAB consolidates apps from multiple frameworks to Blazor to accelerate development and reduce costs.
- Blazor is powering real business value, even if not all are yet on .NET 10.
Breaking Changes: Upgrade Checklist
- HTTP streaming defaults—test your APIs.
- Changes to boot configuration, WebAssembly startup.
- Validate with the official migration guide.
Conclusion (with a Balanced View)
.NET 10 marks a substantial, though evolutionary, step for Blazor:
- Modern security via passkeys (passwords still required for now)
- Enhanced diagnostics and performance transparency
- Notably better startup times and DX, especially in newer Visual Studio releases
- More resilient state management (but persistence is opt-in, not guaranteed)
Many features are in preview or will change at GA—so rely on the official Blazor documentation, GitHub discussions, and .NET release notes.
Have you started building with Blazor .NET 10? Share your experiences in the comments below!
Harikrishnait Solutions—Your .NET Cloud, DevOps, and Modern App Partner