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Wordfence system requirements

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The following are the system requirements for running WordPress with Wordfence.

Wordpress version

We currently require Wordpress 3.9 and above for compatibility

Operating system

A Linux or other Unix type operating system. Windows is not currently supported although we have many reports of Wordfence working on IIS and other Windows web server platforms.

PHP version

PHP version 5.4 or newer. Please note that everything prior to PHP 5.4 is currently considered old and unsupported. There are no security releases for versions prior to PHP 5.4 and there are several important vulnerability fixes that have been released for PHP 5.4, 5.5 and 5.6 which are the currently supported versions at the time of this writing. You can see a nice visual depiction of PHP version history here:


You require a MySQL database. Wordfence will work with MyISAM or the InnoDB storage engine set as your default engine. We don't specify type when creating our tables and will use your defaults.


A minimum of 64 megabytes of memory available for use by PHP. We recommend 128 megabytes for best operation.

We suggest a minimum of 64 megabytes of memory which needs to be available to PHP for you to run Wordfence. Our recommended memory for Wordfence is 128 megabytes.

If you receive an error that looks like the following, you have run out of memory:

Fatal error: Out of memory (allocated 33292288) (tried to allocate 616 bytes) in... [and then some filename] 

This is not a Wordfence bug. It means that your web server does not have enough memory to run WordPress, the plugins and theme you have installed along with Wordfence. Even if you see a Wordfence file mentioned in the above out-of-memory error, remember that WordPress has stored a lot of other data belonging to other plugins, your theme and core in memory. So while the error may mention Wordfence, it's likely that Wordfence was the straw that broke the camels back.

If you do not have enough memory to run Wordfence, please log a support call with your hosting provider asking them to upgrade your memory allowance.

Checking available memory

Knowing how much memory your hosting provider has allocated you can be quite challenging. We provide a basic test tool at the bottom of the Wordfence options page which allocates 80 megabytes of memory to test if you at least have that much. However it seems that some hosting providers vary the amount of memory you have, so this might not be reliable.

You can also check your system information by clicking the link at the bottom of your Wordfence options page to view your web server and PHP environment information. On some installations there may be text titled "memory_limit" which shows your memory limit as set in your PHP.ini file. However this is not present on many modern systems and it's also unreliable because it's possible to limit memory at the web server level and also the operating system level. So instead, if you see an out of memory error, we suggest you contact your site admin or hosting provider and work with them to determine:

  1. What your memory limit is.
  2. If you can upgrade it.


Most hosting environments seem to work well with Wordfence and we have not had reports of a well configured Wordfence installation unable to do it's job due to lack of CPU resources. So you should not have to upgrade or change your CPU configuration to use Wordfence.

We see two kinds of CPU issues. In both cases a hosting provider will contact a customer and tell them that something is accessing /wp-admin/admin-ajax.php with many requests and consuming too many resources. The hosting provider will tell the customer (that's you site administrators) to slow down or face throttling. Here's how you fix either scenario:

Scanning too frequently

If you're using the free version of Wordfence, your scans will run every 24 hours and you can't control this. So if you need to reduce scan frequency, upgrade to Wordfence premium and set your site to scan once a week or something less than once per day.

Live Traffic update in your browser is causing your hosting provider to complain

In this scenario, you can reduce the update frequency of your live traffic. The default is 2 seconds. Reduce this to something like 15 seconds. More info here:

Web Server

Wordfence has been tested on and works with the following web servers or environments:

  • Apache using mod_php
  • LiteSpeed
  • Apache with Nginx in front as reverse proxy.
  • Apache with FastCGI
  • Nginx with PHP5-FPM

WordPress Multi-Site Compatibility

Wordfence is compatible with WordPress multi-site installations. Please note that Wordfence needs to be installed on your Network Admin plugin installation page and will appear as a menu option in the network admin area. Please do not attempt to install Wordfence for each site instance on a multi-site installation.

Please note the following caveat: Wordfence is not compatible with multi-site installations that are using domain mapping. We have seen problems with scan scheduling specifically causing additional scans to be scheduled. You may also experience other issues if you attempt to use Wordfence on a domain-mapped multi-site installation.