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Documentation Status: 
No known problems


PHP 5.6 or higher (as of Backdrop 1.22.0).

The PHP OpenSSL extension is recommended, to allow Backdrop to make outgoing requests using HTTPS. It is required when using the Update Manager.


MySQL or MariaDB 5.0.15 or higher (with PDO)

Web Server

Apache (recommended) or Nginx (details)

Disk Space

A minimum installation requires 15 MB. A website with many contributed modules and themes installed may need 60 MB or more. A lot more space may be required for the database and files or media uploaded by the website's users.

Web Server Details


Apache is the most commonly used web server for Backdrop CMS. Backdrop CMS will work on Apache legacy versions (1.3) as well as stable versions (2.x) hosted on UNIX/Linux, OS X, or Windows.

  • You can use the Apache 'mod_rewrite' extension to allow for clean URLs.
  • The Apache Virtualhost configuration must contain the directive AllowOverride All to allow Backdrop's .htaccess file to be used.
  • Sample Apache Virtualhost configuration:
    DocumentRoot "/path/to/backdrop" ServerName AllowOverride All


Nginx is a commonly used web server that focuses on high concurrency, performance, and low memory usage. Backdrop CMS will work on Nginx legacy versions (0.7.x, 0.8.x, 1.0.x, 1.2.x), stable 1.4.x versions, and mainline 1.5.x versions hosted on UNIX/Linux, OS X, or Windows.

  • Recommended Nginx settings for clean URLs:
    server { 
      listen 80;
      location / {
        root /path/to/backdrop;
        index index.php;
        error_page 404 = @backdrop;
      location @backdrop {
        rewrite ^(.*)$ /index.php?q=$1 last;