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Installation Requirements

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 10, Joomla 4 or WordPress
  • PHP: PHP 8.1 or 8.2 is recommended
  • 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.

Server Environment

Operating System

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.

Optional Libraries

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. 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.

Each CMS has its own policies for which versions are supported or receiving only security support.



  • Drupal 7, Drupal 10 are recommended, although Drupal 8 and 9 which do not have security support also work with CiviCRM.


  • Joomla 4 is recommended, although Joomla 3 which does not have security support also works with CiviCRM.


  • WordPress latest major release is recommended as it is the only one that has official security support, though WordPress 4.9 or newer work with CiviCRM.


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. For example, using PHP 7.4 (or lower) on the command line and using PHP 8.0 (or higher) on the web server has been known to cause issues.

It is also important to ensure that the same PHP extensions/modules are loaded and enabled on both the command line version of PHP and the web server version.

PHP Version

The following recommendations relate to the CiviCRM core codebase. CiviCRM native extensions, and modules and plugins that integrate CiviCRM with CMSes are maintained and released on other schedules. As they typically lag in supporting newer versions of PHP, it is recommended that you test your full site including this other software extensively as part of migrating to a newer version of PHP.

You can find the lifecycle of current PHP versions here.

CiviCRM 5.69 ESR CiviCRM 5.x.x stable
PHP 8.3 compatible and appropriate for early adopters compatible and appropriate for early adopters
PHP 8.2 compatible and recommended compatible and recommended
PHP 8.1 compatible and recommended compatible and recommended
PHP 8.0 compatible but not recommended due to PHP end-of life in Nov 2023 compatible but not recommended due to PHP end-of life in Nov 2023
PHP 7.4 compatible but not recommended due to PHP end-of life in Nov 2022 compatible but not recommended due to PHP end-of life in Nov 2022
PHP 7.3 won't be compatible in 5.75.x ESR
(PHP end-of life in Dec 2021)
not compatible
PHP <7.3 not compatible not compatible
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
5.24 7.0 7.3
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 - 5.69 7.3 7.4
5.70 - 7.4 8.1

PHP Extensions

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
  • PHP File Information - required for spreadsheet support from 5.44 onwards

Required for Third-Party Functionality or CiviCRM Extensions

  • PHP SOAP - required to use the SOAP processor (required for the CiviSMTP service)

PHP Configuration

The following PHP directives is the recommended minimum. These are defined in the php.ini file.


CiviCRM requires MySQL (or compatible) database software.

MariaDB and Percona are forks of the MySQL project and can be used as drop-in replacements for MySQL.

Other database servers (such as PostgreSQL) are not compatible with CiviCRM.

MySQL Version

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.

MySQL Connection

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:

Setting Example Value
Database User Name dbuser
Database User Password dbpassword
Database Server localhost
Database Port 3306
Database Name dbname

Additional URL parameters may be added to support MySQL with TLS.

MySQL Configuration

  • Support for the innodb storage engine is required.
  • The thread_stack configuration variable should be set to 192k or higher.
  • Trigger support is required.
  • ANSI or ANSI_QUOTES is not a supported sql_mode.
  • The ONLY_FULL_GROUP_BY mode should be turned off on production sites - although this is mostly precautionary now.

    • In MySQL 5.7+ the SQL mode ONLY_FULL_GROUP_BY is 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 ONLY_FULL_GROUP_BY from the sql_mode variable. The following SQL query will do the trick.

      SET GLOBAL sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));
    • See also:

    • If you plan to have multiple languages used in your CiviCRM installation it is strongly recommended that you ensure that locale is 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 utf8 to the utf8mb4 character 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):
  • In MySQL 8 the default authentication plugin changes from mysql_native_password to 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_large_prefix and 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:


MySQL Time


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.

WordPress Settings

If you get a MySQL/PHP mismatch warning, under Settings > General set the timezone to a City, not UTC offset. For example, use London not UTC+0.


To support full and consistent display of timestamps, the MySQL server requires timezone data. Many servers include this data by default, but others require you to load it.

Survey of MySQL Servers and Timezone Support
Status Environment Comment
Digital Ocean Specifically tested w/managed MySQL 8.0
Docker mysql Specifically tested w/8.0, 8.0-oracle, and 5.7
Docker mariadb Specifically tested w/10.3 and 10.4
Google Cloud SQL Specifically tested w/5.6. Warning from docs: "not guaranteed to provide up-to-date time settings"
🛠 Azure Database Use az_load_timezone()
🛠 CentOS MariaDB/MySQL Use mysql_tzinfo_to_sql
🛠 cPanel/WHM (with root access) Use mysql_tzinfo_to_sql
🛠 Debian/Ubuntu MariaDB/MySQL Use mysql_tzinfo_to_sql
🛠 Nix MariaDB/MySQL Use mysql_tzinfo_to_sql
Amazon RDS Needs testing/clarification. There are old google-cached forum posts which imply gradual evolution toward support. The current "Local time zone" page seems to affirm, so probably ✅ ... but the docs don't specifically mention session-scoped timezones.
cPanel/WHM (without root access) Needs testing/clarification. If you lack access to mysql_tzinfo_sql (SSH) but have other ways to perform MySQL administration, then you may be able to load pre-generated MySQL timezone data. Key question is whether you have MySQL admin rights.
Pantheon Needs testing/clarification.
WP Engine Needs testing/clarification.


  • (✅) Already support MySQL timezones
  • (🛠) Can support MySQL timezones, with extra setup
  • (❓) Status is not certain
  • (🛑) Cannot support MySQL timezones

To determine if your server currently supports timezones, you can run a test with the CONVERT_TZ() function.

mysql> SELECT CONVERT_TZ("2001-02-03 04:05:00", "GMT", "America/New_York");
| CONVERT_TZ("2001-02-03 04:05:00", "GMT", "America/New_York") |
| 2001-02-02 23:05:00                                          |

If this doesn't perform a proper conversion, then you probably need to load the timezone data.

  • On a self-hosted instance of MySQL or MariaDB, the standard technique is to run mysql_tzinfo_to_sql.
  • If you cannot run mysql_tzinfo_to_sql but have administrative access through another medium, you may load the pre-generated MySQL timezone data. Be sure to load the appropriate SQL file into the database named mysql.
  • Some managed hosts require their own process. For example, "Azure Database" has a special procedure (az_load_timezone()). For managed hosts, you may need to consult their documentation or inquire with support.
Global organizations and service-providers should consider automation.

Timezone definitions change, albeit infrequently. For example, in 1996, Mexico adopted Daylight Savings Time (for most of its timezones); then, in 2022, they dropped DST. For computer-based clocks supporting users in Mexico, those changes require an update to the timezone data. But it's rare -- for Mexico, that represents two major changes (circa 1996 and 2022) over the span of 26 years.

The significance of timezone change is circumstantial. Compare:

  • A local organization may go 20 years without needing an update. When there is a local or national change, it will be covered in the local news. You may get by with infrequent/ad-hoc updates.
  • Globally, in any given year, there will be several locales which do change their rules, and you may not be specifically aware of every change. A global organization or service-provider should consider automatic updates. For example, you might define a system-startup script or a monthly cron-job to run mysql_tzinfo_to_sql.

MySQL Permissions

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 civicrm_user.

ON civicrm.*
TO 'civicrm_user'@'localhost'
IDENTIFIED BY 'realpasswordhere';

Binary Logging

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 SUPER permission (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.