Upgrade the Core

Upgrading to a major release using Composer

This example details how to upgrade from one LTS release to another. In this example, the installation is running TYPO3 version 11.5.34 and the new LTS release is version 12.4.10.

Check which TYPO3 packages are currently installed

TYPO3's Core contains a mix of required and optional packages. For example, typo3/cms-backend is a required package. typo3/cms-sys-note is an optional package and does not need to be installed for TYPO3 to work correctly.

Prior to upgrading, check which packages are currently installed and make a note of them.

Running composer info "typo3/*" will output a list of all TYPO3 packages that are currently installed.

Running composer require

To upgrade a Composer package, run composer require with the package name and version number.

For example, to upgrade typo3/cms-backend run composer require typo3/cms-backend:^12.4.

When upgrading to a new major release, each of TYPO3's packages will need to be upgraded.

Given that a typical installation of TYPO3 will consist of a number of packages, it is recommended that the Composer Helper Tool be used to help generate the Composer upgrade command.


With TYPO3 v12 the typo3/cms-recordlist package was merged into typo3/cms-backend. With TYPO3 v13 the typo3/cms-t3editor package was merged into typo3/cms-backend. Therefore, if you have one of them installed, remove them in your composer.json file before upgrading:

composer remove "typo3/cms-recordlist"
composer remove "typo3/cms-t3editor"

Assuming that the packages below are installed locally, the following example would upgrade each of them to version 12.4.

composer require --update-with-all-dependencies "typo3/cms-adminpanel:^12.4" \
"typo3/cms-backend:^12.4" "typo3/cms-belog:^12.4" "typo3/cms-beuser:^12.4" \
"typo3/cms-core:^12.4" "typo3/cms-dashboard:^12.4" "typo3/cms-felogin:^12.4" \
"typo3/cms-filelist:^12.4" "typo3/cms-filemetadata:^12.4" "typo3/cms-fluid:^12.4" \
"typo3/cms-form:^12.4" "typo3/cms-frontend:^12.4" "typo3/cms-info:^12.4" \
"typo3/cms-install:^12.4" "typo3/cms-linkvalidator:^12.4" "typo3/cms-lowlevel:^12.4" \
"typo3/cms-recycler:^12.4" "typo3/cms-rte-ckeditor:^12.4" "typo3/cms-setup:^12.4" \
"typo3/cms-t3editor:^12.4" "typo3/cms-tstemplate:^12.4" "typo3/cms-viewpage:^12.4"

A typical TYPO3 installation is likely to have multiple third-party extensions installed and running the above command can create dependency errors.

For example, when upgrading from TYPO3 v11 LTS to v12 LTS an error can occur stating that "helhum/typo3-console": "^7.1" is only compatible with v11 LTS, with the new version ^8.1 supporting TYPO3 v12 LTS.

For each of these dependency errors, add the version requirement "helhum/typo3-console:^8.1" to the end of your composer require string and retry the command.

Monitoring changes to TYPO3's Core

The system extensions that are developed and exist within TYPO3's Core are likely to change over time. Some extensions are merged into others, new system extensions are added and others abandoned. These changes are published in the system extensions chapter and can also be found by searching in the changelogs for the extension by its key name.

Next steps

Once the upgrade is complete, there are a set of tasks that need to actioned to complete the process. See Post-upgrade tasks.