Kafka on ZooKeeper After 2026: Apache, Confluent and Cloud End-of-Support Dates

The short answer

Apache Kafka 4.0, released on 18 March 2025, removed ZooKeeper mode. Every release since runs on KRaft only. The project's policy is to make bugfix releases for the last three releases, and the downloads page now lists 4.3, 4.2 and 4.1 as supported. Kafka 3.9, the last line that can run on ZooKeeper, sits under archived releases. Its final patch so far is 3.9.2, published on 21 February 2026.

So the community no longer supports ZooKeeper-mode Kafka. What is left are vendor dates. Confluent Platform 7.8 and 7.9 are the last ZooKeeper-capable Confluent lines, with standard support ending on 2 December 2026 and 19 February 2027. Amazon MSK still supports 3.8.x and 3.9.x and has not published end dates for either.

Every end date for ZooKeeper-mode Kafka

Sources: the Apache Kafka downloads page, Confluent's supported versions and interoperability page, and the Amazon MSK supported versions page, all checked on 4 October 2026.

Apache Kafka: no supported ZooKeeper line

The Apache Kafka release plan aims for three releases a year. Its EOL policy is one line long: the community will attempt bugfix releases as needed for the last three releases. With 4.1, 4.2 and 4.3 in that window, the 3.x series is outside it, and so is ZooKeeper mode.

The 4.0 upgrade notes leave no room for a mixed path. Broker upgrades to 4.0 and later require KRaft mode, with software and metadata versions at 3.3 or later. That makes the ZooKeeper to KRaft migration a 3.x job. You do it on 3.9 (or an earlier 3.x release that supports migration), finalize it, and only then upgrade to 4.x. Clients need care too: 4.0 brokers require Java clients, including Connect and Streams, at 2.1 or later. Our post on Kafka 4.0 client compatibility covers that check.

For the version-by-version history, see the Kafka end-of-life tracker, the Kafka 3.9 page and the Kafka 3.8 page.

Confluent Platform: 7.8 and 7.9 set the pace

Confluent Platform 8.0 removed ZooKeeper, so 7.9 is the last Confluent line that can run it. Confluent gives each minor two years of standard support and adds one more year for Platinum agreements. Gold and below count as standard. The two dates that matter for most ZooKeeper estates are close together:

• 7.8 (Kafka 3.8): standard support ends on 2 December 2026. Confluent Community software on 7.8 ends the same day.
• 7.9 (Kafka 3.9): standard support ends on 19 February 2027, and Platinum on 19 February 2028.

A Confluent customer on 7.8 has under two months of standard support left. Moving to 7.9 buys about eleven weeks more. After that, staying on ZooKeeper under Confluent means Platinum. The detail, including what changes in 8.x, is in Confluent Platform 7.x end of support. If you are weighing whether to stay on Confluent at all, see OSSeva vs Confluent.

Amazon MSK: open-ended, but not under your control

MSK has already ended support for 3.6.0 (1 June 2026) and 3.7.x (1 September 2026). It lists no end date for 3.8.x or 3.9.x. AWS says 3.9 is the last version that supports both ZooKeeper and KRaft, and that it will provide extended support for 3.9 for a minimum of two years from its release date. The MSK table gives 3.9.x a release date of 21 April 2025, which points to no earlier than April 2027. AWS has not tied that commitment to a calendar date, so plan against the published table, not the estimate.

Two MSK rules shape the risk. A cluster on a version past its end of support date is auto-upgraded to the recommended version, at any time after that date and without notice. MSK also phases out creating new clusters on any version with a published end date. Once AWS publishes a date for 3.8 or 3.9, the clock is AWS's, not yours. The MSK specifics, including in-place migration to KRaft, are covered in Amazon MSK Kafka version end of support.

What to do with a ZooKeeper cluster now

There are two real paths, and most estates with many clusters end up using both.

Migrate to KRaft

This is the destination for every ZooKeeper cluster. The Apache migration runs in phases. You upgrade to a migration-capable 3.x release, provision a KRaft controller quorum, put the brokers into migration mode, and move them to KRaft. Then you finalize. Until you finalize, you can revert to ZooKeeper mode, and after that you cannot. Once finalized, the cluster can take the 4.x upgrade and rejoin the supported release window. Our ZooKeeper to KRaft migration runbook walks through each phase for self-managed 3.x clusters.

Run a patched 3.9 while the migration waits

Not every cluster can migrate this quarter. Some sit behind change freezes. Some carry old clients inside products you do not control. Others are simply queued behind higher-risk clusters. For those, the risk is running unpatched brokers and an unpatched ZooKeeper ensemble in the meantime. OSSeva provides extended support for Kafka 3.x on ZooKeeper. That means backported CVE fixes for Kafka 3.x brokers, 3.9 included, and for the ZooKeeper ensemble beneath them, plus hands-on help to run and finalize the KRaft migration when each cluster is ready. See Kafka support for the version list.

Common questions

Which Kafka version is the last to support ZooKeeper?

Kafka 3.9. Apache Kafka 4.0 removed ZooKeeper mode, and Confluent Platform 7.9, which ships Kafka 3.9, is the last Confluent line with ZooKeeper.

Is Kafka 3.9 still supported by the Apache community?

No. The project supports the last three releases, currently 4.1, 4.2 and 4.3. The 3.9 line is listed under archived releases, and its latest patch is 3.9.2 from 21 February 2026.

Can I upgrade a ZooKeeper cluster straight to Kafka 4.0?

No. Brokers must be running in KRaft mode before the 4.0 upgrade, so the ZooKeeper to KRaft migration has to be completed on 3.x first.

When does Amazon MSK end support for Kafka 3.9?

AWS has not published a date. It has committed to extended support for 3.9 for at least two years from its release date.