# Pre-release packages


When a package is ready for testing, its developer ensures basic test coverage and confirms that the package passes internal testing. The package also needs at least preliminary documentation, an updated changelog, and licensing.

Pre-release packages are partially tested and verified to use safely with the current version of the Unity Editor. Unity supports pre-release packages and guarantees their production readiness when the Editor enters the current cycle’s long-term support (LTS) phase. For more information about the pre-release state and the lifecycle of packages, refer to [package states and lifecycle](/engine/6000.5/manual/packages-list/packages/upm-lifecycle.md).

Pre-release packages appear in the details view with the  label and in the list view with the  label.

By default, pre-release packages don't appear in the list of packages you can install. However, you can force the Package Manager to display them by enabling **Show Pre-release Package Versions** in [Project Settings](/engine/6000.5/manual/unity-editor/editor-settings-reference/comp-manager-group/class-package-manager.md).

> **Note:**
>
> Before Unity Editor 2021.1, Package Manager used the **Preview** state to identify packages that were experimental or risky but otherwise mature, and packages not fully validated for production. Starting with 2021.1, the **Preview** state no longer exists, and packages can either be **Experimental** or **Pre-release**. This provides a clearer distinction between packages that are mature but risky to use, and packages that are almost fully mature.

For a list of stable packages released for this version of the Editor, refer to [Released packages](/engine/6000.5/manual/packages-list/packages-all/pack-safe.md).

(There are no Pre-released packages for this release.)