Development environment IntelliJ IDEA 2025.3 released in Islands Theme

Software manufacturer JetBrains has released version 2025.3 of numerous of its development environments, including IntelliJ IDEA, which primarily focuses on Java and Kotlin, WebStorm for JavaScript/TypeScript, and PyCharm for Python. What the IDEs have in common is that they now appear in the new Islands Theme. In addition, there are specific updates for their respective use cases.

IntelliJ IDEA: Switch to K2 and Support for Java 25

IntelliJ IDEA 2025.3 offers support for the current versions of Spring Boot 4, Spring Framework 7, Java 25, and Vitest 4, among others. The development team has also marked the K1 mode for Kotlin as deprecated, as it migrated to the K2 mode. The newer K2 compiler has been considered stable since the release of Kotlin 2.0 about a year and a half ago and is expected to provide significant performance improvements.

Online conference on Kotlin

The online conference betterCode() Kotlin will showcase innovations for the programming language on February 24 and 25, 2026, and feature deep dives. The first day focuses on mobile and cross-platform development. The second day will present new features of the programming language and provide insights into the Koog framework for AI agents.

There are also updates for some functions: Among other things, Find Usages previously only displayed file names, which was not always clear in complex codebases. Now, relative paths are sometimes displayed as well. For accessibility, the JetBrains team has corrected the functionality of the magnifier in Windows and improved many UI areas for handling screen readers. In addition, native support for the AI agents Junie and Claude Agent is now available. In total, 800 bug reports and usability issues were resolved in this release.

Furthermore, something fundamental is changing with IntelliJ IDEA: The Ultimate Edition and the Community Edition are now handled as a single distribution, instead of separately as before. This is intended to simplify the development process from JetBrains' side. A similar innovation is found in PyCharm, where the Community Edition and the Pro Edition have been merged. The paid Pro version can be tried out directly from the IDE.

Islands Theme in JetBrains IDEs

Not only IntelliJ IDEA, but also other JetBrains IDEs use the Islands Theme in version 2025.3. This new default view is intended to be clearer and more understandable. Among other things, it offers rounded corners, changed spacing, and a more clearly visible boundary for tool windows. Active tabs are also now marked more clearly than before, as JetBrains demonstrates:

Detailed information on IntelliJ IDEA 2025.3 can be found in the blog post announcing the release, the "What's New" page, and the "What's Fixed" page.

Version 2025.3 has also been released for other IDEs such as PyCharm, PhpStorm, GoLand, WebStorm, and CLion. The development of the IDE Fleet, on the other hand, has been discontinued, in favor of a planned new IDE based on it with a focus on Agentic Development.

(mai)