--- title: "Module \"Maintenance\" (System)" manual: "TYPO3 Explained" version: "14.3" permalink: "https://docs.typo3.org/permalink/t3coreapi:admin-tools-maintenance@14.3" source: "Administration/Tools/Maintenance/Index.rst" rendered: "2026-10-01T15:20:05+00:00" --- # Module "Maintenance" (System) {#admin-tools-maintenance} This module has been moved from Admin tools to Settings. Only available if [`typo3/cms-install`](https://packagist.org/packages/typo3/cms-install) is installed. The backend module **System > Maintenance** offers tools to system maintainers that are necessary during development or updates. Some of the tools available here include: - [Flush TYPO3 and PHP cache](https://docs.typo3.org/permalink/t3coreapi:flush-typo3-and-php-cache@14.3) - [Analyze database structure](https://docs.typo3.org/permalink/t3coreapi:analyze-database-structure@14.3) - [Remove temporary assets](https://docs.typo3.org/permalink/t3coreapi:remove-temporary-assets-1@14.3) - [Rebuild PHP autoload information](https://docs.typo3.org/permalink/t3coreapi:rebuild-php-autoload-information@14.3) - [Clear persistent database tables](https://docs.typo3.org/permalink/t3coreapi:clear-persistent-database-tables-1@14.3) - [Create administrative user](https://docs.typo3.org/permalink/t3coreapi:create-administrative-user@14.3) - [Reset backend user preferences](https://docs.typo3.org/permalink/t3coreapi:reset-backend-user-preferences@14.3) - [Manage language packs](https://docs.typo3.org/permalink/t3coreapi:manage-language-packs@14.3) ## Flush TYPO3 and PHP cache {#clear-caches} By clicking the button **Flush cache** you can flush all caches. This is necessary during development if you changed files like [Fluid templates](https://docs.typo3.org/permalink/t3coreapi:fluid-templates@14.3), [TypoScript files](https://docs.typo3.org/permalink/t3coreapi:typoscript@14.3), or PHP files. It is also necessary to flush caches after installing or updating extensions. You can achieve the same effect by calling: ```bash ddev typo3 cache: flush ``` > [!NOTE] > Flushing the cache via the "Clear cache" buttons in the > Top Bar does not have the same effect. It does not flush > PHP related caches. ## Analyze database structure {#database-analyser} Before running a database compare, try [flushing the cache](https://docs.typo3.org/permalink/t3coreapi:admin-tools-maintenance-flush-cache@14.3). This flushes cached TCA definitions that might inadvertently determine the database structure. Despite its name, this tool not only analyzes the database structure but also offers to fix it for you. Database changes can be necessary when TCA files have changed or extensions installed / updated. ### Add tables and columns using the database analyzer {#database-analyser-add} When the database analyser suggests adding columns or tables you can safely do so. ### Change or remove columns and tables in the database analyzer {#database-analyser-remove} Before you remove tables or columns, make a [database backup](https://docs.typo3.org/permalink/t3coreapi:security-backup-database@14.3). The database analyzer gives you the possibility to *remove* old and redundant tables and columns from the database. See also [Database compare during update and installation](https://docs.typo3.org/permalink/t3coreapi:database-upgrade@14.3). It executes queries to remove these tables and columns so that your database corresponds to the structure required in the new TYPO3 version. > [!NOTE] > TYPO3 does not immediately delete tables and fields. Instead, it adds > a `zzz_deleted_*` prefix to the table names. > > This lets you verify whether they’re truly obsolete or just mistakenly marked > for deletion. Once confirmed, you can permanently remove them via the wizard. When you then click "Compare current database with specification" again and you see the message "Database schema is up to date. Good job!", then all database updates have been applied. ## Remove temporary assets {#remove-temporary-assets} After an upgrade to a new major version, it might be necessary to delete temporary files which TYPO3 saves in the `typo3temp/` folder. In the **System > Maintenance** module, click on the **Remove Temporary Assets > Scan temporary files** button and select the appropriate folders. ## Rebuild PHP autoload information {#rebuild-autoload-information} This tool in module **System > Maintenance** is only available in classic mode installations. If PHP classes are not found even after [flushing the cache](https://docs.typo3.org/permalink/t3coreapi:admin-tools-maintenance-flush-cache@14.3), rebuilding the autoload information might help. In Composer mode installations you can use the following Composer command to achieve the same thing: ```bash composer dump-autoload ``` ## Clear persistent database tables {#clear-persistent-database-tables} You can use this tool to clear persistent database tables like `sys_log` and `sys_history` manually. If you need to clear these tables on a regular basis, set up a task in the module **Administration > Scheduler**. ## Create administrative user {#admin-tools-maintenance-create-admin} This tool can be used to create a new administrative backend user with or without maintainer privileges. You can also create new backend users using the console: ```bash vendor/bin/typo3 backend:user:create ``` and in the module **Administration > Users**. Using this module, admins can create new admins but not system maintainers. Until TYPO3 V14 this module was called System > Backend Users. ## Reset backend user preferences {#clear-user-settings} You might consider clearing the Backend user preferences. This can avoid problems if something in the upgrade requires this. Open **System > Maintenance**, scroll to "Reset user preferences" and click "Reset backend user preferences". ## Manage language packs {#update-translations} In the module **System > Maintenance**, open tool "Manage language packs". You can add additional languages to be downloaded or update the language packs for languages already in use.