# SimpleITK 3.0.0 Beta 1

**URL:** https://discourse.itk.org/t/simpleitk-3-0-0-beta-1/7767
**Category:** Announcements
**Tags:** python, csharp, r, java, simpleitk
**Created:** [May 22, 2026, 12:45pm UTC](https://discourse.itk.org/t/simpleitk-3-0-0-beta-1/7767 "2026-05-22T12:45:41Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![blowekamp](https://discourse.itk.org/user_avatar/discourse.itk.org/blowekamp/32/79_2.png) [@blowekamp](https://discourse.itk.org/u/blowekamp)
#### Post date: [May 22, 2026, 12:45pm UTC](https://discourse.itk.org/t/simpleitk-3-0-0-beta-1/7767/1 "2026-05-22T12:45:41Z")

</div>

**Announcing the SimpleITK 3.0.0b1 Beta Release!**

This beta release is a major milestone for SimpleITK 3.0, featuring new functionality and improvements including experimental integration of SimpleElastix into the binary distributions.

## Installing SimpleITK

Complete instructions on getting started with SimpleITK including downloading binaries or building SimpleITK can be found on the SimpleITK [Read the Docs web page](https://simpleitk.readthedocs.io/en/master/index.html).

### Python Binary Downloads

Python binary wheels are available for download. To install this beta release from Test PyPI or the GitHub release page:

**From Test PyPI:**

```auto
python -m pip install --upgrade pip
python -m pip install --pre --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple/ SimpleITK

```

Note: Due to space limitation on Test PyPI, published releases are not kept long term on the test distribution hub.

**From GitHub release page:**  
`pip install --upgrade --pre simpleitk --find-links https://github.com/SimpleITK/SimpleITK/releases/tag/v3.0.0b1`

The binary distribution contains wheels built on the Python 3.11 stable API (see [PEP 384](https://peps.python.org/pep-0384/)) and should work with Python versions 3.11 and later. Additionally, this release provides wheels specifically for Python 3.10 and free-threaded Python 3.14t.

### Getting Started

To get started with pre-compiled Java or C# bindings, building the R binding, or building SimpleITK from source code, see the [Getting Started Guide](https://simpleitk.readthedocs.io/en/main/gettingStarted.html).

# Release Highlights

## 🎉 SimpleElastix Now Included in Binary Distributions!

As an experiment, **SimpleElastix is included in SimpleITK binary distributions**! Previously, SimpleElastix required building SimpleITK from source with special flags. This major enhancement brings powerful image registration capabilities to all users without needing custom builds.

SimpleElastix provides access to the elastix registration framework, enabling advanced deformable image registration directly through SimpleITK’s `ElastixImageFilter` and `TransformixImageFilter` classes. A key advantage of elastix is its [parameter zoo](https://lkeb.ml/modelzoo/) - a curated collection of turnkey parameter settings for various registration scenarios, from simple rigid alignment to complex multi-modal deformable registration. This makes SimpleElastix particularly valuable for medical image analysis, image alignment, and multi-modal registration tasks without requiring extensive parameter tuning expertise.

## SimpleITK in R for Windows!

SimpleITK 3.0.0b1 continues support for building SimpleITK with R wrapping for all major operating systems, including Windows. It is recommended to use the [SimpleITKRInstaller](https://github.com/SimpleITK/SimpleITKRInstaller) to configure standard or custom builds. This release adds support for the new R 4.6.0.  
Expand commentComment on line R43Resolved

## Free-Threaded Python 3.14 Support

This release includes **Python wheels for free-threaded CPython 3.14** (`cp314t` in wheel filenames). The Global Interpreter Lock (GIL) is now optional in CPython ([PEP 703](https://peps.python.org/pep-0703/)), enabling true parallel multithreading on multi-core systems. SimpleITK has been updated to declare the Python module as GIL-free for compatibility with free-threaded CPython.

While this change affects native Python code and requires compatible wheels, standard Python wheels continue to unlock the GIL during ITK code execution for parallel processing. Read more about [free-threaded Python on python.org](https://docs.python.org/3/howto/free-threading-python.html).

## ITK 5.4.6

This distribution is based on the Insight Toolkit 5.4.6 release. Please see the ITK release notes for details.

## Migration Guide for Version 3.0

A comprehensive [migration guide](https://simpleitk.readthedocs.io/en/main/migration_guides/migrationGuide3.0.html) is now available to help users transition from SimpleITK 2.x to 3.0.

## What’s Changed

- Align Elastix/Transformix API with elastix PR #417 by @blowekamp in [Align Elastix/Transformix API with elastix PR #1417 by blowekamp · Pull Request #2526 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2526)
- Remove outdated cdash exceptions for warnings and errors by @blowekamp in [Remove outdated cdash exceptions for warnings and errors by blowekamp · Pull Request #2528 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2528)
- Use additional PR branch name in ccache key by @blowekamp in [Use additional PR branch name in ccache key by blowekamp · Pull Request #2529 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2529)
- DOC: Update Sphinx docs for v3.0.0a3 changes by @blowekamp in [DOC: Update Sphinx docs for v3.0.0a3 changes by blowekamp · Pull Request #2530 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2530)
- Add migration guide for version 3.0 by @blowekamp in [Add migration guide for version 3.0 by blowekamp · Pull Request #2533 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2533)
- DOC: Add release notes and update documentation infrastructure by @blowekamp in [DOC: Add release notes and update documentation infrastructure by blowekamp · Pull Request #2534 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2534)
- COMP: Update ITK to release-5.4 branch hash 2026-02-26 by @blowekamp in [COMP: Update ITK to release-5.4 branch hash 2026-02-26 by blowekamp · Pull Request #2535 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2535)
- Add myst\_parser to Sphinx Docs requirements by @blowekamp in [Add myst\_parser to Sphinx Docs requirements by blowekamp · Pull Request #2537 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2537)
- DOC: Update requirements and ReadTheDocs config by @blowekamp in [DOC: Update requirements and ReadTheDocs config by blowekamp · Pull Request #2538 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2538)
- Separately backport gersemi CMake formatting for FindR.cmake by @blowekamp in [Separately backport gersemi CMake formatting for FindR.cmake by blowekamp · Pull Request #2541 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2541)
- Update FindR to detect R.dll on windows. by @blowekamp in [Update FindR to detect R.dll on windows. by blowekamp · Pull Request #2542 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2542)
- Update Elastix to Superbuild 5.3.1 by @blowekamp in [Update Elastix to Superbuild 5.3.1 by blowekamp · Pull Request #2540 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2540)
- Coverage image by @blowekamp in [Coverage image by blowekamp · Pull Request #2532 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2532)
- Update FindR to detect R.dll on windows. - for release by @blowekamp in [Update FindR to detect R.dll on windows. - for release by blowekamp · Pull Request #2546 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2546)
- DOC: Update phrasing in documentation. by @zivy in [DOC: Update phrasing in documentation. by zivy · Pull Request #2548 · SimpleITK/SimpleITK · GitHub](https://github.com/SimpleITK/SimpleITK/pull/2548)