NanoXLSX version 3 will be released soon

[rabanti-github]

Dear NanoXLSX users and contributors,

NanoXLSX has come a long way. Now, almost 7.5 years after the first release and about 3.5 years after the release of version 2.0, the time has nearly come: version 3.0 is on the starting line. Several release candidates are already available (at the time of writing, RC6).

The final release is currently planned for the end of January or February 2026. There is still some work to be done, but overall things are looking good.

What changes with version 3?

NanoXLSX v3 is now based on a package system. The NanoXLSX library is split into NanoXLSX.Core (core components), NanoXLSX.Reader (functions for reading workbooks), and NanoXLSX.Writer (functions for writing workbooks). Before the final release, NanoXLSX.Formatting (including support for inline formatting, among other things) will most likely be added as well.

Functionally, not a great deal has changed. Most changes are in the area of styles, along with many additional features. The most common adjustment required for existing code will likely be namespace changes.

A complete migration guide is available here:
https://github.com/rabanti-github/NanoXLSX/blob/dev-v3/MigrationGuide.md

Questions, bug reports, and feedback are of course always very welcome 😄.

If you’d like to learn more about the motivation behind these changes, there is also a blog post on the topic:
From Monolith to Modules: Why NanoXLSX Finally Broke Its Own Traditions