Requirements

TYPO3 version

Composer packages for TYPO3 can be found on packagist.org down to version 6.2.0: typo3/cms-*.

Composer

Composer is a program that is written in PHP. Instructions for downloading and installing Composer can be found on getcomposer.org.

Folder structure

If the root folder of your project is identical to your web root folder, you need to change this. Composer will add a vendor/ folder to your project root, and if your project root and your web root are identical, this can be a security issue: files in the vendor/ folder could be directly accessible via HTTP request.

Bad:

$ tree typo3_root
├── index.php
├── fileadmin/
├── typo3/
├── typo3conf/
└── typo3temp/

You will need a web root folder in your project. You can find many tutorials with different names for your web root folder. The truth is: the name does not matter because we can configure it in the settings in a later step. We will use public/ in our example.

Good:

$ tree typo3_root
└── public/
    ├── index.php
    ├── fileadmin/
    ├── typo3/
    ├── typo3conf/
    └── typo3temp/

If you do not have such a web root directory, you will have to refactor your project before proceeding. Please be aware that you may need to tell your web server about the changed web root folder if necessary.

Code integrity

Your project must have the TYPO3 Core and all installed extensions in their original state. If you applied manual changes to the files, these will be lost during the migration steps.