-- required in legacy installations

The ext_emconf.php is used in legacy installations not based on Composer to supply information about an extension in the Admin Tools > Extensions module. In these installations the ordering of installed extensions and their dependencies are loaded from this file as well.

It is also needed for Writing functional tests with the typo3/testing-framework <https://github.com/TYPO3/testing-framework> in v8 and earlier.

Changed in version 11.4

In Composer-based installations, the ordering of installed extensions and their dependencies is loaded from the composer.json file, instead of ext_emconf.php

The only content included is an associative array, $EM_CONF[extension key]. The keys are described in the table below.

This file is overwritten when extensions are imported from the online repository. So do not write your custom code into this file - only change values in the $EM_CONF array if needed.


    'title' => 'Extension title',
    'description' => 'Extension description',
    'category' => 'plugin',
    'author' => 'John Doe',
    'author_email' => 'john.doe@example.org',
    'author_company' => 'some company',
    'state' => 'stable',
    'version' => '1.0.0',
    'constraints' => [
        'depends' => [
            'typo3' => '12.0.0-12.4.99',
        'conflicts' => [
        'suggests' => [

$_EXTKEY is set globally and contains the extension key.


Data type



string, required

The name of the extension in English.


string, required

Short and precise description in English of what the extension does and for whom it might be useful.



Version of the extension. Automatically managed by extension manager / TER. Format is [int].[int].[int]



Which category the extension belongs to:

  • be

    Backend (Generally backend-oriented, but not a module)

  • module

    Backend modules (When something is a module or connects with one)

  • fe

    Frontend (Generally frontend oriented, but not a "true" plugin)

  • plugin

    Frontend plugins (Plugins inserted as a "Insert Plugin" content element)

  • misc

    Miscellaneous stuff (Where not easily placed elsewhere)

  • services

    Contains TYPO3 services

  • templates

    Contains website templates

  • example

    Example extension (Which serves as examples etc.)

  • doc

    Documentation (e.g. tutorials, FAQ's etc.)

  • distribution

    Distribution, an extension kickstarting a full site



List of requirements, suggestions or conflicts with other extensions or TYPO3 or PHP version. Here's how a typical setup might look:

'constraints' => [
    'depends' => [
        'typo3' => '11.5.0-12.4.99',
        'php' => '7.4.0-8.1.99'
    'conflicts' => [
        'templavoilaplus' => ''
    'suggests' => [
        'news' => '9.0.0-0.0.0'
List of extensions that this extension depends on. Extensions defined here will be loaded before the current extension.
List of extensions which will not work with this extension.
List of suggestions of extensions that work together or enhance this extension. Extensions defined here will be loaded before the current extension. Dependencies take precedence over suggestions. Loading order especially matters when overriding TCA or SQL of another extension.

The above example indicates that the extension depends on a version of TYPO3 between 11.4 and 12.4 (as only bug and security fixes are integrated into TYPO3 when the last digit of the version changes, it is safe to assume it will be compatible with any upcoming version of the corresponding branch, thus .99). Also the extension has been tested and is known to work properly with PHP 7.4. and 8.1 It will conflict with "templavoilaplus" (any version) and it is suggested that it might be worth installing "news" (version at least 9.0.0). Be aware that you should add at least the TYPO3 and PHP version constraints to this file to make sure everything is working properly.

For legacy installations, the ext_emconf.php file is the source of truth for required dependencies and the loading order of active extensions.



Which state is the extension in

  • alpha

    Alpha state is used for very initial work, basically the extension is during the very process of creating its foundation.

  • beta

    Under current development. Beta extensions are functional, but not complete in functionality.

  • stable

    Stable extensions are complete, mature and ready for production environment. Authors of stable extensions carry a responsibility to maintain and improve them.

  • experimental

    Experimental state is useful for anything experimental - of course. Nobody knows if this is going anywhere yet... Maybe still just an idea.

  • test

    Test extension, demonstrates concepts, etc.

  • obsolete

    The extension is obsolete or deprecated. This can be due to other extensions solving the same problem but in a better way or if the extension is not being maintained anymore.

  • excludeFromUpdates

    This state makes it impossible to update the extension through the Extension Manager (neither by the update mechanism, nor by uploading a newer version to the installation). This is very useful if you made local changes to an extension for a specific installation and do not want any administrator to overwrite them.



Deprecated since version 12.1

When loading or unloading extensions using the extension manager, all caches are always cleared. Extensions that want to keep compatibility with both TYPO3 v11 and v12 should keep the setting until v11 compatibility is dropped from the extensions.



Author name


email address

Author email address



Author company



To get better class loading support for websites in legacy mode the following information can be provided.

Extensions having one folder with classes or single files

Considering you have an Extbase extension (or an extension where all classes and interfaces reside in a Classes folder) or single classes you can add the following to your ext_emconf.php file:

'autoload' => [
   'classmap' => [

Extensions using namespaces

If the extension has namespaced classes following the PSR-4 standard, then you can add the following to your ext_emconf.php file:

'autoload' => [
   'psr-4' => [
      'Vendor\\ExtName\\' => 'Classes'



Same as the configuration "autoload" but it is only used if the ApplicationContext is set to Testing.

Deprecated configuration

See older versions of this page.