News

Uno Platform Studio and 'Hot Design' Reach General Availability

• By David Ramel
• 05/09/2025

Uno Platform, a .NET-centric open source project for building single-codebase apps across web, Windows, iOS, Android, macOS, and Linux, this week announced v6.0 of its flagship offering, which introduces a zero-install, web-based IDE for rapid cross-platform development, alongside a modernized app architecture that embraces MVU and .NET-style extensions.

The main highlight of Uno Platform 6.0 is Uno Platform Studio, which provides a browser-based development environment that lets developers build, preview, and download cross-platform .NET apps with no installation required, leveraging WebAssembly for instant live previews.

Key functionality of the studio includes Hot Design, described by the company as a next-gen visual designer. As we detailed in the November 2024 article, "Uno Platform Unveils 'Hot Design' Tool for Cross-Platform .NET Apps," it basically eliminates the traditional separation between design-time and runtime, allowing developers to modify visual designs directly in the running application, with those changes reflected immediately in the source code.

It also features Hot Reload for any target in any IDE, along with a design-to-code Figma plugin.

"Uno Platform Studio is built on top of the open-source Uno Platform, and gives you a highly productive, end-to-end workflow to build, edit, and ship real .NET apps in record time -- all from a single codebase," the company said in a May 7 announcement, which detailed those three features mentioned above:

• Hot Design: The industry-first visual designer for cross-platform .NET apps. Instantly pause and edit your running app from any IDE, on any OS -- even with complex UIs -- and see changes live as you work.
• Hot Reload: Confidently tweak and test code in real time. See visual feedback instantly with our App Indicator confirming your changes were applied -- no guessing, no restarts.
• Design-to-Code: Go from Figma to functional UI in one click. Generate clean, maintainable, production-ready XAML or C# markup that looks like it was hand-written.

Also highlighted was an architectural revamp.

"Secondly, we re-engineered the whole Uno Platform to make sure it is lean, fast and super-easy to use, but also to prepare it for the premium tooling and AI innovation to come," the announcement said. "On mobile, we've observed up to 3X performance improvements in startup time, down to 0.5 seconds."

Other highlights of the new update include:

• Updated Project Templates: New templates for Blank, MVU, and Quick Start projects, aligned with modern Uno.Extensions architecture and minimal .NET startup patterns.
• Enhanced MVU Tooling: Improved support for the Model-View-Update pattern with cleaner syntax, better tooling, and tighter integration with Uno.Extensions.
• WebAssembly Tooling Enhancements: Faster live previews and startup times for WebAssembly targets, supporting better in-browser testing and prototyping.
• Downloadable Solution Export: Ability to export projects built in Uno Platform Studio as full Visual Studio or VS Code solutions, ready for local development across Windows, macOS, and Linux.
• Improved Source Generator Support: Expanded use of source generators to handle boilerplate for navigation, DI, and configuration, improving performance and reducing reflection-based runtime overhead.
• Expanded Uno.Extensions Libraries: Additional helpers and abstractions added to the Uno.Extensions stack, including improved navigation models and lifecycle handling.
• Streamlined Developer Onboarding: First-run experience significantly improved with in-browser app creation, guided templates, and automatic solution packaging.
• New MediaPlayer Control: A cross-platform media playback component supporting audio/video with consistent behavior across Uno targets.
• New WebView2 Control: Integration of the Chromium-based WebView2 for embedding modern web content in Uno apps on Windows and select platforms.

Read the announcement for details of an upcoming May 15 webinar that will explain more about the release.