It appears that htmx has an alpha release of version 4.

Wait, I thought Carson said there would be no more versions of htmx (remember stability as a feature?)

Well, correction, he said there would be no version 3 😁...

The main thrust of the version change is swapping out XMLHttpRequest (mainly used for IE support) to the more modern fetch() method.

The change will bring about explicit inheritance calls for attributes contained within the declared element. Also, cached history (by default) will be gone, which was a source of pain for a subset of history-related issues with v2.0.

Additionally, the change will enable streaming responses and server-sent events (SSE) right out of the box. There are a few other new features highlighted on the post, so be sure to check it out.

As far as a timeline is concerned, don't expect a release until early/mid 2026. It will then be marked as latest in early 2027. However, rest assured, if upgrading gives you the heeby-jeebies, version 2.0 will continue to be supported in perpetuity!