Vaadin Launches Swing Modernization Toolkit, Enabling Java Teams to Run Desktop Applications in the Browser

New solution provides incremental path from Java Swing to modern web applications while preserving existing business logic

TURKU, Finland, Feb. 10, 2026 /PRNewswire/ -- Vaadin, the leading provider of Java web application frameworks, today announced the general availability of Swing Modernization Toolkit, a solution that enables organizations to run their existing Java Swing desktop applications in the browser and modernize them incrementally, without a full rewrite.

Swing Modernization Toolkit addresses a growing challenge for enterprises: millions of lines of business-critical Java Swing code that still work but face increasing pressure from users who expect browser-based access, IT teams seeking centralized deployment, and development organizations struggling to hire Swing-experienced developers.

"Many organizations have been told their options are limited, time and budget consuming and can result in a complete re-write—either in JavaScript or another framework," said Steven Grandchamp, CEO at Vaadin. "That approach fails more often than it succeeds. Swing Modernization Toolkit gives teams a realistic alternative: get the existing app to run in the browser immediately, unlocking new potential and then modernize at whatever pace makes sense for the business."

Three-Phase Modernization Approach

Swing Modernization Toolkit separates the problem of browser delivery from UI modernization through a phased approach:

Phase 1: Browser Access — Existing Swing applications run on a server-side JVM with the UI rendered in the browser. Only minor changes to the app are required to enable multi-tenancy and readiness for the web. Users access the application via URL from any device.

Phase 2: Incremental Modernization — Teams replace Swing views with modern web views screen by screen, prioritizing based on business impact. Existing Java business logic, services, and domain models remain intact.

Phase 3: Complete Transition — Over time, the application becomes a fully modern Java web application built for the web, with no Swing dependencies remaining. The gap between Phase 2 and Phase 3 can be significant, while Phase 1 already enables new user-facing features.

Key Capabilities

Swing Modernization Toolkit includes:

• Run Swing in the Browser — Existing Java Swing applications run immediately in any modern browser with very minimal code changes required
• Automated View Conversion — Converts most Swing views to matching Vaadin views automatically, providing a working baseline faster than manual rebuilding
• Swing/AWT Runtime Compatibility — Drop-in implementations for common Swing and AWT behaviors ensure applications work correctly in a browser context
• Mixed-Mode Operation — Both Swing views and new web views coexist during the transition period

Availability

Swing Modernization Toolkit is available now. Organizations interested in assessing their Swing applications can request an evaluation at vaadin.com/swing.

About Vaadin

Vaadin is the leading platform for building modern web applications in Java. With Vaadin, Java developers create full-stack web applications using a single language—no JavaScript, HTML, or CSS required. Vaadin's component library and server-side architecture enable teams to build complex business applications faster while maintaining enterprise-grade security and performance. Thousands of organizations worldwide rely on Vaadin, from startups to Fortune 500 companies. Learn more at vaadin.com.

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SOURCE Vaadin