function app hard deadline of deprecating or removing 1.x runtime

KK 20 Reputation points
2026-07-14T08:24:06.5466667+00:00

Azure Functions Runtime 1.x support ends on 14 September 2026. Microsoft documentation states that customers can continue using Runtime 1.x after this date, but it will no longer be supported.

Can Microsoft confirm:

  1. Whether there is a planned service retirement date for Runtime 1.x?
  2. Whether Microsoft intends to disable or remove Runtime 1.x from Azure in the future?
  3. If yes, what is the currently published timeline and notification period?

We are performing application lifecycle and risk assessments and require clarification on any hard retirement date beyond the support-end date.

Azure Functions
Azure Functions

An Azure service that provides an event-driven serverless compute platform.

0 comments
Answer accepted by question author
Rukmini 43,915 Reputation points Microsoft External Staff Moderator
2026-07-14T08:31:42.0533333+00:00

Hello @KK

From the docs, Azure Functions runtime v1 “support ends on” September 14, 2026. Importantly, end of support does not mean your app is turned off immediately—apps continue running, but they won’t receive security patches or bug fixes (and you’ll lose support coverage). The guidance is to migrate to v4.x.

That said, with the information provided here, the docs do not include additional details about:

  • a separate “hard retirement”/service retirement date after Sept 14, 2026, or
  • whether Microsoft will later disable or remove runtime v1 from Azure,
  • nor any published future timeline/notification period for such a retirement/disablement event.
  1. Planned service retirement date for Runtime 1.x?
    • Based on the information currently available, there is no announced service retirement date for Runtime 1.x. The documented milestone is the end of support on September 14, 2026.
  2. Will Microsoft disable/remove Runtime 1.x in the future?
    • There is currently no published information indicating that Runtime 1.x will be disabled or removed. The available documentation states that after September 14, 2026, applications will continue to run; however, the runtime will no longer receive support, including security updates and bug fixes. .
  3. If yes, published timeline + notification period?
    • At this time, Microsoft has not published a timeline or notification period for the retirement or removal of Runtime 1.x beyond the announced end-of-support date.

Hence,

  • Support end: September 14, 2026 for runtime v1.
  • Operational behavior around that date: apps won’t stop immediately, but will no longer get security patches/bug fixes/support.
  • Recommendation: migrate to Azure Functions v4 (the docs strongly recommend this for full support).

If the resolution was helpful, kindly take a moment to click on User's imageand click on Yes for was this answer helpful. And, if you have any further query do let us know.

Was this answer helpful?

1 person found this answer helpful.

1 additional answer

Sort by: Oldest
Most helpful Newest Oldest

  1. AI answer

    2026-07-14T08:24:23.96+00:00

    The currently published information confirms only this:

    • Azure Functions runtime 1.x remains GA until September 14, 2026.
    • Support ends for version 1.x on September 14, 2026.
    • Microsoft highly recommends migrating apps to version 4.x.
    • The documentation states that versions 2.x and 3.x are out of support, and for those versions Microsoft explicitly says existing apps can still be created and deployed, but they are not eligible for new features, security patches, performance optimizations, and related service support until upgraded.

    For runtime 1.x specifically, the published material provided here does not state:

    • a separate service retirement date beyond September 14, 2026
    • a published plan to disable or remove runtime 1.x from Azure
    • a published notification period for any future hard retirement

    So, based on the currently published information in scope, the only confirmed date is the end of support on September 14, 2026. No additional hard retirement timeline is published here for Azure Functions runtime 1.x.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.