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Azure Functions language stack support policy

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This article explains the support policy for the language stacks supported by Azure Functions. Guidance is language-specific. Make sure to choose your preferred development language at the top of the article.

Retirement process

The Functions runtime includes the Functions host and programming language-specific workers. To maintain full-support coverage when running your functions in Azure, Functions support aligns with end-of-life support for a given language. To help you keep your apps up-to-date and supported, Functions implements a phased reduction in support as language stack versions reach their end-of-life dates. Generally, the retirement date coincides with the community end-of-life date of the given language.

  • Notification phase:

    The Functions team sends you notification emails about upcoming language version retirements that affect your function apps. When you receive this notification, you should prepare to upgrade these apps to use to a supported version.

  • Retirement phase:

    After the language end-of-life date, function apps that use retired language versions can still be created and deployed, and they continue to run on the platform. However, these apps aren't eligible for new features, security patches, and performance optimizations until after you upgrade them to a supported language version.

    Important

    If you're running function apps using an unsupported runtime or language version, you might encounter issues and performance implications and are required to upgrade before receiving support for your function app. As such, you're highly encouraged to upgrade the language version of such an app to a supported version. TO learn how, see Update language stack versions in Azure Functions.

Retirement policy exceptions

Any Functions-supported exceptions to language-specific retirement policies are documented here:

There are currently no exceptions to the general retirement policy.

Use these resources to better understand and plan for language support-related changes in your function apps.

Resource Details
Language version support timelines .NET support policy page
Configuring language versions Isolated worker model
In-process model
Retired runtime versions* v2.x: .NET Core 2.1
v3.x: .NET Core 3.1 & .NET 5**
Resource Details
Language version support timelines Node.js release page on GitHub
Configuring language versions Setting the Node version
Retired runtime versions* v2.x: Node.js 10 & 8
v3.x: Node.js 14, 12, & 10
Resource Details
Language version support timelines Java support on Azure and Azure Stack
Configuring language versions Update the stack configuration
Retired runtime versions* v2.x: Java 8
v3.x: Java 11 & 8
Resource Details
Language version support timelines PowerShell Support Lifecycle
Configuring language versions Changing the PowerShell version
Resource Details
Language version support timelines Python developer's guide
Configuring language versions Changing Python version
Retired runtime versions* v2.x: Python 3.7
v3.x: Python 3.9, 3.8, 3.7

*Indicates the highest language stack level for no-longer-supported versions of the Functions runtime, such as runtime version 2.x.

**.NET 5 was only supported for C# apps running in the isolated worker model.

For the language levels currently supported by Azure Functions, see Languages by runtime version.

Frequently asked questions

This section provides you with answers to questions that are frequently asked about language support policies.

Which versions of my preferred language does Functions currently support?

For the up-to-date list of supported language stack versions, see Supported languages in Azure Functions.

How long will Functions continue to support my language version?

Functions support aligns with the end-of-life date published by the community for a given language stack. For the expected end-of-life date of currently supported versions, see Supported languages in Azure Functions.

What happens when my runtime version reaches the end of support?

After a previously supported Functions runtime version reaches its end-of-support, Microsoft no longer provides bug fixes, security updates, or patches. Apps using retired versions may also face performance degradation. You must upgrade to a supported version to maintain security and stability.

Can I continue to use an unsupported language stack or runtime version?

You can continue to use previously supported language stacks and Functions runtime versions beyond the end-of-support date. However, you must take into account that unsupported runtime versions don't receive updates, security patches, or official support from Microsoft. Your apps might also face performance degradation when using retired runtime versions.

How do I upgrade my function app to a newer supported language stack or runtime version?

To make sure that your app is compatible with both the latest supported Functions runtime version and the latest version of your language stack, see Update language stack versions in Azure Functions

How do I check which language stack and runtime version is being used by my function app?

Azure provides these methods to check the current runtime version used by your function app:

The language stack used by your function app is determined based on the value of the FUNCTIONS_WORKER_RUNTIME application setting. For more information, see Work with application settings.

To learn more about how to upgrade your function app's language version, see these articles: