News

Uno Platform Takes 'Hot Design' for Cross-Platform .NET Apps to Public Beta

• By David Ramel
• 03/10/2025

Uno Platform has taken its "Hot Design" feature to public beta, extending the "Hot Reload" paradigm with functionality to visually edit and refine a running application in real-time.

Announced during the Microsoft Build 2024 developer conference last November, it can seamlessly synchronize design changes with source code across multiple platforms.

While Uno Platform provides a free, open-source core platform, the final Hot Design feature will be available only in the for-pay Pro edition of its Uno Platform Studio developer productivity tooling suite, though developers can try it out with the Community edition of the studio.

"Hot Design is a new take on Visual Designers," the company said in a March 6 post announcing the public beta. "We believe past attempts for WYSIWYG designers were good for decades past, but not for today, where modern Visual Designers and AI-assisted development will be essential parts of development workflow."

While similar real-time UI editing functionality exists in different implementations that are usually tied to specific editors and IDEs, Hot Design transforms a running application into an interactive design environment, accessible from any IDE on any operating system.

Uno Platform compared its approach to alternatives in terms of productivity.

To try it out, developers must sign in with a Uno Platform account, with guidance noting these points:

• Hot Design is now available on all platforms in beta, with the Desktop platform (-desktop target framework) currently offering the most stable and reliable experience. Other platforms are still undergoing stabilization. See the list of known issues.
• Hot Design does not support C# Markup and is only available with XAML and .NET 9. Additionally, Hot Design is not supported for the WinAppSDK target framework at this time.
• Hot Design relies on Hot Reload for updates, so be sure to check the current support for your OS, IDE, and target platforms before testing.

Key features listed by the organization include:

• Achieve the Fastest Inner DevLoop: With a single click, turn your running app into a visual Designer. Another click returns you to your app, keeping you in your workflow without disruption.
• Design in Real Time: Modify your app's UI instantly while it's running, enabling fast, interactive development.
• Leverage Your Favorite IDE: Seamlessly integrate with Visual Studio, VS Code, or JetBrains Rider on any OS, with IDE-agnostic support.
• Synchronize Code and Designer: Reflect changes instantly between the Designer and code, ensuring your live app and XAML remain a single source of truth.
• Integrate Live Data: Connect your UI to data sources intuitively and see real-time updates to data bindings as you build, simplifying the process.
• Work Directly with Real Data: Skip mock data creation by working with actual data sources from your running app, gaining a true-to-life feel of your app's behavior. Mock data is also supported for added flexibility.
• Reuse Custom & 3rd-Party Controls: Incorporate custom and third-party UI components effortlessly while maintaining a consistent look and behavior across platforms.
• Manage State with Flexibility: Work seamlessly with MVVM or MVUX to consume real-time data while keeping UI logic separate from core logic.
• Apply Styles Easily: Enhance your app's UI and UX with predefined styles, applied effortlessly in just a few clicks — no coding required.
• Explore Responsive Layouts: Test layout options with a single click and instantly visualize how your app adapts to different devices and form factors.
• Switch Themes Effortlessly: Toggle between light and dark modes with one click to ensure a consistent user experience across color schemes.
• Design on Remote Devices: Fine-tune your UI directly on remote devices or emulators, instantly seeing changes without the need for constant redeployment.
• Simplify Property Management: Use Smart Properties to quickly find, modify, and bind key UI properties without leaving the live design environment, saving time and effort.

Uno Platform has yet to decide the pricing for the Pro edition of Uno Platform Studio, which will offer Hot Design along with other functionality available in the Community edition such as Hot Reload.

"Both community and pro SKUs are going to grow in terms of items / benefits offered, which we are going to announce at a later date," the organization said. "Lastly, Uno Platform remains an open-source project under the Apache 2.0 license. The tooling in Uno Platform Studio is powerful but optional for developing cross-platform .NET applications with Uno Platform."

To help developers try it out, Uno Platform published "Create a Counter App with Hot Design."