# 13 Version compatibility

#### Supported agents

Zabbix agents starting with version 1.4 are compatible with Zabbix 4.0.
However, you may need to review the configuration of older agents as
some parameters have changed, for example, parameters related to
[logging](https://www.zabbix.com/documentation/3.0/manual/installation/upgrade_notes_300#changes_in_configuration_parameters_related_to_logging)
for versions before 3.0.

To take full advantage of new and improved items, improved performance
and reduced memory usage, use the latest 4.0 agent.

#### Supported Zabbix proxies

Both Zabbix 4.0 proxies and Zabbix 4.0 server are supported to work only
with Zabbix 4.0 server and Zabbix 4.0 proxies respectively.

::: noteimportant
It is known to be possible to start an upgraded
server and have older, yet unupgraded proxies report data to a newer
server (the proxies can't refresh their configuration though). This
approach, however, is not recommended and not supported by Zabbix and
choosing it is entirely at your own risk. For more information, see the
[upgrade procedure](/manual/installation/upgrade).
:::

#### Supported XML files

XML files, exported with 1.8, 2.0, 2.2, 2.4, 3.0, 3.2 and 3.4 are
supported for import in Zabbix 4.0.

::: noteimportant
In Zabbix 1.8 XML export format, trigger
dependencies are stored by name only. If there are several triggers with
the same name (for example, having different severities and expressions)
that have a dependency defined between them, it is not possible to
import them. Such dependencies must be manually removed from the XML
file and re-added after import.
:::