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Before upgrading or migrating

When updating from one major Apache Tomcat® version a newer one, please make sure that the JVM that is installed on your system supports at least the required Java version. While it is possible that older versions of Tomcat may not be compatible with newer JVMs, all the currently supported Apache Tomcat versions (9.0.x, 10.1.x and 11.0.x) are known to run correctly on Java 17 JVMs.

When migrating from one major Tomcat version to another (e.g. from Tomcat 9 to Tomcat 10, or from Tomcat 10 to Tomcat 11), you should not copy the configuration files from the old version to the new version. The recommended approach is to start with the default configuration of the new version of Apache Tomcat and to adjust it as necessary.

When migrating from one minor release to another minor release within the same major release (e.g. from Tomcat 9.0.29 to Tomcat 9.0.30) you can retain the configuration files, but you should check to see if any defaults have changed and/or if any new elements have been added and adjust your configuration files accordingly.

Migration Guides

For upgrading between 11.0.x versions, see the upgrading section of the Tomcat 11.0.x Migration Guide.

For migration from 10.1.x to 11.0.x, see the Tomcat 11.0.x Migration Guide.

For upgrading between 10.1.x versions, see the upgrading section of the Tomcat 10.1.x Migration Guide.

For migration from 10.0.x to 10.1.x, see the Tomcat 10.1.x Migration Guide.

For upgrading between 10.0.x versions, see the upgrading section of the Tomcat 10.0.x Migration Guide.

For migration from 9.0.x to 10.0.x, see the Tomcat 10.0.x Migration Guide.

For upgrading between 9.0.x versions, see the upgrading section of the Tomcat 9.0.x Migration Guide.

For migration from 8.0.x / 8.5.x to 9.0.x, see the Tomcat 9.0.x Migration Guide.

For upgrading between 8.5.x versions, see the upgrading section of the Tomcat 8.5.x Migration Guide.

For migration from 8.0.x to 8.5.x, see the Tomcat 8.5.x Migration Guide.

For upgrading between 8.0.x versions, see the upgrading section of the Tomcat 8.0.x Migration Guide.

For migration from 7.0.x to 8.0.x, see the Tomcat 8.0.x Migration Guide.

For upgrading between 7.0.x versions, see the upgrading section of the Tomcat 7.0.x Migration Guide.

For migration from 6.0.x to 7.0.x, see the Tomcat 7.0.x Migration Guide.

For upgrading between 6.0.x versions, see the upgrading section of the Tomcat 6.0.x Migration Guide.

For migration from 5.5.x to 6.0.x, see the Tomcat 6.0.x Migration Guide.