1. What is Contao (and what does the Contao Manager do)?
Contao is a PHP-based open-source CMS that you install and update via Composer.
The Contao Manager is a web-based interface that takes care of Composer tasks for you (installation/update, cache, extensions).
Key requirements:
PHP 8.1+ (depending on the chosen Contao version)
Enabled ``allow_url_fopen``
PHP functions ``proc_open/proc_close``
PHP extensions Intl & OpenSSL
Database (MySQL/MariaDB)
Webserver document root pointing to the ``/public`` folder of the projectFurther information:
[System requirements](https://docs.contao.org/manual/de/installation/systemvoraussetzungen/)
[Contao Manager](https://docs.contao.org/manual/de/installation/contao-manager/)
[Downloads (Manager & Contao)](https://contao.org/de/download)
Recommendation: For new projects, use a supported LTS version (see Downloads).2. Step by Step (Hetzner/konsoleH)
Requirements
Your domain/subdomain is set up and accessible via HTTPS.
The database (name, user, password, host) has been created.
For the SSH variant, you need Webhosting Level 9 or higher.2.1 Provide Contao Manager
Variant A: via SSH (recommended, from Webhosting plan Level 9 upwards)
ssh contaoy@<wwwXXX> cd ~/public_html wget https://download.contao.org/contao-manager/stable/contao-manager.phar
Variant B: via WebFTP (konsoleH → Extras → WebFTP)
Download the Contao Manager from the download page: https://contao.org/de/download
Upload contao-manager.phar via WebFTP into ``public_html``.
Rename the file to contao-manager.phar.php only after the upload (to avoid text/binary transfer issues).2.2 Open Contao Manager & create user
In your browser, open ``https://<contao.example.com>/contao-manager.phar.php``.
Create a manager user with a strong password.
Note: The Manager does not require its own database.
[Documentation](https://docs.contao.org/manual/de/installation/contao-manager/)2.3 Check PHP settings (if message appears)
If the system check shows something like:
PHP Web Process – The PHP setting "allow_url_fopen" is not enabled on the server.
→ go to konsoleH → Settings → Configuration → PHP configuration and set
"allow_url_fopen" = On. Also make sure Intl and OpenSSL are available and that proc_open/proc_close are allowed.
Note: ``allow_url_fopen`` cannot be enabled via ``.htaccess`` – only in the hosting provider’s PHP configuration.2.4 Webserver setup / Set document root to /public
Open the "Webserver Setup" in the Contao wizard.
In konsoleH → Settings → Configuration → Server configuration (``.htaccess``)
set the start directory to public.
Go back to the wizard and confirm the message:
“The directory structure … is set up correctly!” → Continue.
Background: In current Contao projects, ``/public`` is the public web folder. (In special cases, ``web`` may be used – then it’s defined in ``composer.json``.)2.5 Install Contao
In the Manager, click ``Setup`` if prompted.
Choose the Contao version (recommended: LTS, see Downloads) and start installation.
On webhosting with limited RAM, enable the Composer Resolver Cloud (option in Manager).
[Documentation](https://docs.contao.org/manual/de/installation/contao-manager/)2.6 Connect & update database
Enter your DB credentials → Save.
Click Check database → if “Your database is not up to date…”
run Execute, then Confirm & Close.
Recommendation: Enable MySQL Strict Mode.
Continue.
[Installation docs](https://docs.contao.org/manual/de/installation/)2.7 Create backend account & login
Create the backend user (username, name, email, password) → Add account.
Log in to the backend at: https://<contao.example.com>/contao/
[Backend/Administration](https://docs.contao.org/manual/de/administration/backend/)3. Next Steps
Create page structure & content:
[Page structure](https://docs.contao.org/manual/de/seitengestaltung/seitenstruktur/)
[Content elements](https://docs.contao.org/manual/de/artikelverwaltung/inhaltselemente/)
[Extensions/Themes (via Contao Manager)](https://docs.contao.org/manual/de/installation/contao-manager/)
Security & operations:
Use Manager/Backend exclusively over HTTPS.
Use strong passwords, optionally 2FA.
Restrict access to ``/contao-manager.phar.php`` after setup, or remove/rename the file (only needed for updates).
[Follow updates & releases](https://contao.org/de/news)4. Troubleshooting
4.1. “allow_url_fopen is not enabled”
→ Cause: PHP option disabled
→ Solution: Enable in konsoleH → PHP configuration (not via .htaccess)
4.2. Manager stuck at “Installing Composer dependencies…”
→ Cause: Not enough RAM / Composer resolver timeout
→ Solution: Enable Composer Resolver Cloud in Manager; set memory_limit ≥ 256M
4.3. “No Contao installation has been found”
→ Cause: Setup not run or wrong start directory
→ Solution: Run setup in Manager; check start directory is /public
4.4. Frontend 404 / redirect loop
→ Cause: Rewrite not active or wrong doc root
→ Solution: Check /public as start directory
Apache: enable .htaccess / mod_rewrite
NGINX: set try_files … /index.php… correctly
4.5. “Database not up to date”
→ Cause: Pending migrations
→ Solution: Run “Execute” in Install Tool/Manager → then “Confirm & Close”
4.6. Backend not accessible
→ Cause: Wrong path or cache issue
→ Solution: Access backend via /contao/; clear cache in Manager if needed