# JAX v0.3.22

- Product: JAX (https://whatsnew.fyi/product/jax)
- Vendor: Google
- Date: 2022-10-11
- Version: v0.3.22
- Original notes: https://github.com/jax-ml/jax/releases/tag/jax-v0.3.22
- Permalink: https://whatsnew.fyi/product/jax/releases/v0.3.22

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

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- **changed** — Set JAX_PLATFORMS=tpu,cpu as default setting in TPU initialization so JAX will raise an error if TPU cannot be initialized instead of falling back to CPU, with options to override using JAX_PLATFORMS='' for automatic backend selection or JAX_PLATFORMS=cpu for CPU-only usage
- **removed** — Remove several test utilities from jax.test_util that were deprecated in JAX v0.3.8

* Changes
  * Add `JAX_PLATFORMS=tpu,cpu` as default setting in TPU initialization,
  so JAX will raise an error if TPU cannot be initialized instead of falling
  back to CPU. Set `JAX_PLATFORMS=''` to override this behavior and automatically
  choose an available backend (the original default), or set `JAX_PLATFORMS=cpu`
  to always use CPU regardless of if the TPU is available.
* Deprecations
  * Several test utilities deprecated in JAX v0.3.8 are now removed from
    {mod}`jax.test_util`.