Ensure that your system meets the following requirements before installing or upgrading CiviCRM.
If you are curious what technologies other organizations are using to run CiviCRM, you can look at the CiviCRM Stats.
A recommended server environment should typically meet these guidelines:
- Operating system: Linux
- CMS: Backdrop, Drupal 7, Drupal 9, Joomla, or WordPress
- PHP: 7.2, 7.3, 7.4 -- with configuration and extension requirements. PHP 8.0 is supported from 5.40. PHP 8.1 is supported from 5.55
- MySQL: MySQL 5.7.5+ or MariaDB 10.2+ -- with configuration requirements
Other environments may also meet the system requirements. The following sections present requirements more precisely.
If your server meets all of the requirements described on this page, CiviCRM should function correctly. There are no explicit operating system requirements. However, it's worth noting that CiviCRM is far more widely deployed and tested on UNIX-based operating systems, in particular Linux (e.g. Ubuntu, Debian, etc.), than with Microsoft Windows. You can still use CiviCRM fine from Windows desktops when the hosting environment runs Linux.
In general, CiviCRM is a demanding web application which requires substantial server resources. It may not perform well on all hosting platforms. Learn more about choosing your hosting platform.
Some people report better performance in some circumstances when rendering PDF files (e.g. reports or invoices). CiviCRM has a configuration option to use a system binary for WKHTMLtoPDF. https://wkhtmltopdf.org/ You can find this setting under "System Settings" > "Misc".
Another reason to use it is that is solves the issue of how to handle unicode fonts needed for some languages.
A CMS, or Content Management System, is a type of application which controls and manages the content of a website. CiviCRM must be installed within one of these compatible CMS platforms.
See the page on choosing a CMS for more information about the advantages and disadvantages of each compatible CMS platform.
- Backdrop 1.0 or newer is required.
- Drupal 7 or Drupal 9 is required.
- Joomla 3.x.x is required.
- WordPress 4.9 or newer is required.
PHP Version on the Command Line¶
The PHP version used on the command line is important and should match the version used by the web server. Using PHP 7.1 (or lower) on the command line and using PHP 7.2 (or higher) on the web server can cause issues.
It is also important to ensure that the same PHP extensions/modules are loaded on the command line and the web server.
|CiviCRM 5.51 ESR||CiviCRM 5.x.x stable|
|PHP 8.1||incompatible||compatible from CiviCRM 5.55 however not recommended yet until the extension ecosystem catches up.|
|PHP 8.0||compatible however not recommended yet until the extension ecosystem catches up.||compatible from CiviCRM 5.39 however not recommended yet until the extension ecosystem catches up.|
|PHP 7.4||compatible and recommended||compatible and recommended|
|PHP 7.3||compatible and recommended||compatible but not recommended due to to PHP end-of life in Dec 2021|
|PHP 7.2||compatible and recommended - but see note below about resaving the SMTP password||compatible but not recommended due to to PHP end-of life in Dec 2020 but see note below about resaving the SMTP password|
|PHP 7.1||incompatible||incompatible as of 5.35.0|
|PHP 7.0||incompatible||incompatible as of 5.25.0|
Historical PHP Versions
The table below gives information on PHP minimum and recommended version compatibility for old versions of CiviCRM:
|CiviCRM Version||PHP Minimum Version||PHP Recommended Version|
|5.1 - 5.5||5.5||7.0|
|5.6 - 5.9||5.5||7.1|
|5.10 - 5.13||5.6||7.2|
|5.14 - 5.23||7.0||7.2|
|5.25 - 5.34||7.1||7.3|
|5.35 - 5.36||7.2||7.3|
|5.37 - 5.45||7.2||7.4|
|5.46 - current||7.3||7.4|
To install these extensions, you will typically install a separate package within your server's package manager (e.g.
apt-get on Ubuntu).
Required for CiviCRM Core¶
- PHP BCMath - required for calculating financial values in CiviCRM Core.
- PHP Curl - required for many payment processors, the extension manager, and the CiviCRM News dashlet.
- PHP DOM XML - required by CiviCase.
- PHP Multibyte - required for internationalisation and proper encoding of fields.
- PHP Zip - required for unzipping auto-downloaded extensions so they can be installed from the browser.
- PHP INTL - required for outputting localized formatted number strings from CiviCRM 5.28 onwards
Required for Third-Party Functionality or CiviCRM Extensions¶
- PHP SOAP - required to use the SOAP processor (required for the CiviSMTP service)
PHP 7.1 and the MCrypt library¶
PHP MCrypt - the MCrypt extension is no longer recommended for new installations. From CiviCRM 5.34 onwards MCrypt is no longer needed.
PHP 7.2 Compatibility
7.2 upgrade warning - 7.2 does not support MCrypt and if MCrypt is not installed the SMTP password (if entered) will need to be re-saved once you update your PHP version to 7.2.
PHP 7.1 cannot access SMTP credentials
CiviCRM will incorrectly attempt to decrypt the SMTP password using the MCrypt library when executed using PHP 7.1. If PHP 7.2 or higher was used to save the SMTP password. This can occur if the PHP version on the command line does not match the web server version.
The following PHP directives is the recommended minimum. These are defined in the php.ini file.
Don't use MAMP XCache
Several people have reported "white screen of death" trying to run CiviCRM with MAMP's XCache enabled (check MAMP > Preferences > PHP > Cache).
CiviCRM requires MySQL (or compatible) database software.
Other database servers (such as PostgreSQL) are not compatible with CiviCRM.
Your MySQL version should be 5.7.5 or greater or MariaDB 10.2 or greater.
Historical MySQL Versions
The table below gives information on MySQL minimum and recommended version compatibility for old versions of CiviCRM:
|CiviCRM Version||MySQL Minimum Version||MySQL Recommended Version||MariaDB Minimum Version||MariaDB Recommended Version|
|5.26 - 5.27||5.5||5.7|
|5.28 - 5.33||5.6.5||5.7||10.4|
|5.34 - 5.51||5.7 (unenforced)||5.7||10.0.2||10.4|
|5.52 - Latest||5.7 (enforced)||5.7||10.2||10.4|
As of version 5.24 CiviCRM has been shown to be able to run on MySQL 8 through the execution of our test matrix. All of the Content Management Systems support MySQL 8, CiviCRM MySQL 8 support was being tracked in this issue for MySQL 8 support. Backdrop supports MySQL 8 as of 1.17.2, Drupal 7 as of 7.76 Supports MySQL 8, All versions of Drupal 9 support MySQL 8, Current versions of WordPress and Joomla appear to be compatible with MySQL 8.
By default, new installations of CiviCRM will copy the MySQL connection details from the CMS, creating a shared database. It is also possible to install CiviCRM on a separate database. As a rule of thumb:
- A shared database works well for small deployments (eg a few thousand records and a single administrator or developer).
- Separate databases work well for large deployments (eg a million records and multiple administrators/developers).
If you are unsure which style fits better, consider some trade-offs:
- Initial setup: The shared database can be setup automatically. To use a separate database, you must create the second one.
- "Views" integration: On Drupal 7 / Backdrop, the "Views" integration can query MySQL data from both CMS and Civi. This works easily with a shared database, but it requires effort with separate databases.
- Backups: If you have a small data-set and a good backup mechanism, the shared database is easier to backup -- it's only one job.
- Large datasets: If the CMS dataset and Civi dataset grow large (eg millions of records), then separating the databases will allow better resource-management.
- Development/staging process: If you have different people working on the system code or system configuration, then they may need to work with different subsets of the data. (Ex: A theme developer may need access to the CMS data but not the Civi data. For an application developer, that could be reversed.) With separate databases, it may be easier to negotiate the workflow.
If your choose to use separate databases, then you need connection details for the second database. Connections are represented in URL format. For example:
The example URL captures several pieces of information:
|Database User Name||
|Database User Password||
Additional URL parameters may be added to support MySQL with TLS.
- Support for the
innodbstorage engine is required.
thread_stackconfiguration variable should be set to 192k or higher.
- Trigger support is required.
ANSI_QUOTESis not a supported
ONLY_FULL_GROUP_BYmode should be turned off on production sites - although this is mostly precautionary now.
- In MySQL 5.7+ the SQL mode
ONLY_FULL_GROUP_BYis enabled by default which causes some errors due to some of CiviCRM's SQL queries that were written with the assumption that this mode would be disabled.
Administrators are advised to turn off this SQL mode by removing the string
sql_modevariable. The following SQL query will do the trick.
SET GLOBAL sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));
- If you plan to have multiple languages used in your CiviCRM installation it is strongly recommended that you ensure that
localeis set to a UTF8 locale and also ensure that you set utf8 as the standard encoding for MySQL. To alter locale you can configure as per Ubuntu instructions, Debian, CentOS. To set the default encoding for MySQL you should follow the steps provided in this Stack Overflow post
- In order to support a future data migration from
utf8mb4character set, it is recommended, though not yet required, to add the following configuration directives on MySQL 5.5 or 5.6 (these are the default values on MySQL 5.7):
[mysqld] innodb_large_prefix=true innodb_file_format=barracuda innodb_file_per_table=true
- In MySQL 5.7+ the SQL mode
In MySQL 8 the default authentication plugin changes from
caching_sha2_password. This may cause issues with your PHP layer. Fortunately you can revert this change by specifying your chosen authentication plugin in your MySQL configuration:
Also in MySQL 8 the following variables, used fairly extensively in CiviCRM installs, have been removed
innodb_file_format. In MySQL 8 binary logging is also turned on by default which many users may want to turn off, this can be achieved by adding to your MySQL configuration file:
CiviCRM performs various operations based on dates and times – for example, deactivating expired records or triggering scheduled reminders. To perform these operations correctly, the dates and times reported by PHP and MySQL should match. If the dates or times are mismatched, then one or more of the following may be the problem:
- PHP and MySQL may be running on different servers, and the clocks may be out-of-sync. Configuring automatic clock synchronization is the best solution.
- PHP, MySQL, and/or the operating system may be configured to use different default timezones. Verify the configuration of each.
- The content management system (Drupal, Joomla, or WordPress) or one of its plugins may manipulate the timezone settings without informing CiviCRM's. You may wish to post to Stack Exchange or Mattermost about your problem. Please include any available details about the timezone settings in the operating system, PHP, MySQL, and the CMS; if you have any special CMS plugins or configuration options which may affect timezones, please report them.
MySQL/PHP Time Mismatch Warning - WordPress¶
If you get a MySQL/PHP mismatch warning, under
Settings > General set the timezone to a City, not UTC offset. For example, use
The permissions you'll need to assign to the MySQL user that CiviCRM uses will depend on your version of MySQL. The following example assumes you have a database called
civicrm and a MySQL user called
GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES, TRIGGER, CREATE ROUTINE, ALTER ROUTINE, REFERENCES, CREATE VIEW, SHOW VIEW ON civicrm.* TO 'civicrm_user'@'localhost' IDENTIFIED BY 'realpasswordhere';
If you want to enable binary logging you will need to choose one of the following. Either:
Add the following line to your configuration file. The location of the configuration file depends on your operating system and database server you can find more information for MySQL here and for MariaDB here.
log_bin_trust_function_creators = 1
(See the MySQL manual reference for more information.)
Or give the
SUPERpermission (even if your MySQL version is greater than 5.1.6).
GRANT SUPER ON *.* TO 'civicrm_user'@'localhost';
(More information on triggers is available in the MySQL documentation about Binary Logging of Stored Programs.)
Installing on certain Cloud Providers¶
When installing on certain cloud providers (AWS, Azure) where you are using database as a service, you will not have access to the my.cnf but you can generally use Database Parameter Groups or in Azure to set the parameters such as the
log_bin_trust_function_creators as appropriate. On Azure running with DB as a service there needs to be a change made to the installation code as per the answer on Stack Exchange here. This is due to Azure not permitting connections to databases without credentials.