---
title: Compatibility
description:
weight: 7
tags: ['kafka', 'docs']
aliases:
keywords:
type: docs
---
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With the release of Kafka 4.0, significant changes have been introduced that impact compatibility across various components. To assist users in planning upgrades and ensuring seamless interoperability, a comprehensive compatibility matrix has been prepared.
# JDK Compatibility Across Kafka Versions
<table>
<tr>
<th>
Module
</th>
<th>
Kafka Version
</th>
<th>
Java 11
</th>
<th>
Java 17
</th>
<th>
Java 23
</th> </tr>
<tr>
<td>
Clients
</td>
<td>
4.0.0
</td>
<td>
✅
</td>
<td>
✅
</td>
<td>
✅
</td> </tr>
<tr>
<td>
Streams
</td>
<td>
4.0.0
</td>
<td>
✅
</td>
<td>
✅
</td>
<td>
✅
</td> </tr>
<tr>
<td>
Connect
</td>
<td>
4.0.0
</td>
<td>
❌
</td>
<td>
✅
</td>
<td>
✅
</td> </tr>
<tr>
<td>
Server
</td>
<td>
4.0.0
</td>
<td>
❌
</td>
<td>
✅
</td>
<td>
✅
</td> </tr> </table>
**Note: Java 8 is removed in Kafka 4.0 and is no longer supported.**
# Server Compatibility
<table>
<tr>
<th>
KRaft Cluster Version
</th>
<th>
Compatibility 4.0 Server (dynamic voter)
</th>
<th>
Compatibility 4.0 Server (static voter)
</th> </tr>
<tr>
<td>
before 3.2.x
</td>
<td>
❌
</td>
<td>
❌
</td> </tr>
<tr>
<td>
3.3.x
</td>
<td>
❌
</td>
<td>
✅
</td> </tr>
<tr>
<td>
3.4.x
</td>
<td>
❌
</td>
<td>
✅
</td> </tr>
<tr>
<td>
3.5.x
</td>
<td>
❌
</td>
<td>
✅
</td> </tr>
<tr>
<td>
3.6.x
</td>
<td>
❌
</td>
<td>
✅
</td> </tr>
<tr>
<td>
3.7.x
</td>
<td>
❌
</td>
<td>
✅
</td> </tr>
<tr>
<td>
3.8.x
</td>
<td>
❌
</td>
<td>
✅
</td> </tr>
<tr>
<td>
3.9.x
</td>
<td>
✅
</td>
<td>
✅
</td> </tr>
<tr>
<td>
4.0.x
</td>
<td>
✅
</td>
<td>
✅
</td> </tr> </table>
**Note: Can’t upgrade server from static voter to dynamic voter, see [KAFKA-16538](https://issues.apache.org/jira/browse/KAFKA-16538).**
## Client/Broker Forward Compatibility
<table>
<tr>
<th>Kafka Version</th>
<th>Module</th>
<th>Compatibility with Kafka 4.0</th>
<th>Key Differences/Limitations</th>
</tr>
<tr>
<td rowspan="3">0.x, 1.x, 2.0</td>
<td>Client</td>
<td>❌ Not Compatible</td>
<td>
Pre-0.10.x protocols are fully removed in Kafka 4.0 ([KIP-896](https://cwiki.apache.org/confluence/x/K5sODg)).
</td>
</tr>
<tr>
<td>Streams</td>
<td>❌ Not Compatible</td>
<td>
Pre-0.10.x protocols are fully removed in Kafka 4.0 ([KIP-896](https://cwiki.apache.org/confluence/x/K5sODg)).</td>
</tr>
<tr>
<td>Connect</td>
<td>❌ Not Compatible</td>
<td>
Pre-0.10.x protocols are fully removed in Kafka 4.0 ([KIP-896](https://cwiki.apache.org/confluence/x/K5sODg)).</td>
</tr>
<tr>
<td rowspan="3">2.1 ~ 2.8</td>
<td>Client</td>
<td>⚠️ Partially Compatible</td>
<td>
More details in the [Consumer](/40/documentation.html#upgrade_400_notable_consumer), [Producer](/40/documentation.html#upgrade_400_notable_producer), and [Admin Client](/40/documentation.html#upgrade_400_notable_admin_client) section.</td>
</tr>
<tr>
<td>Streams</td>
<td>⚠️ Limited Compatibility</td>
<td>
More details in the [Kafka Streams](/40/documentation.html#upgrade_400_notable_kafka_streams) section.</td>
</tr>
<tr>
<td>Connect</td>
<td>⚠️ Limited Compatibility</td>
<td>
More details in the [Connect](/40/documentation.html#upgrade_400_notable_connect) section.</td>
</tr>
<tr>
<td rowspan="3">3.x</td>
<td>Client</td>
<td>✅ Fully Compatible</td>
<td>—</td>
</tr>
<tr>
<td>Streams</td>
<td>✅ Fully Compatible</td>
<td>—</td>
</tr>
<tr>
<td>Connect</td>
<td>✅ Fully Compatible</td>
<td>—</td>
</tr>
</table>
Note: Starting with Kafka 4.0, the `--zookeeper` option in AdminClient commands has been removed. Users must use the `--bootstrap-server` option to interact with the Kafka cluster. This change aligns with the transition to KRaft mode.