Which is better for a new project in 2026: Wicket 9 or Wicket 10, and why?

For a brand-new project starting in 2026, Wicket 10 is almost always the right default, though the reasoning is about ecosystem alignment more than either branch being objectively "better" software.

Wicket 10 targets Java 17 (with Java 21 compatibility) and the Jakarta EE namespace, which matches where the broader Java ecosystem has already moved — modern servlet containers, current versions of Spring, and most actively maintained libraries have made or are making the same javax-to-jakarta transition. Starting a new project on Wicket 9 means deliberately choosing an older baseline with no long-term upside, since there's nothing a new project would gain from targeting Java 11 and the javax namespace on purpose.

The one legitimate reason to pick Wicket 9 for something new would be an unavoidable dependency on a specific javax-based library or container that hasn't been ported to Jakarta yet and can't reasonably be swapped out — a real but increasingly rare constraint that's the exception, not the default reasoning.