The “allowed memory size exhausted” error is one of the more common technical issues WordPress site owners encounter, typically appearing as a white screen with an error message referencing a specific memory limit in bytes. While the immediate fix often involves increasing the available memory, understanding why the error occurred in the first place helps prevent it from recurring.
This guide explains what causes the WordPress memory limit exhausted error and how to resolve it properly.
What the Memory Limit Exhausted Error Means
WordPress runs on PHP, which has a configured limit on how much memory a single script is allowed to use at once, as a safeguard against runaway processes consuming excessive server resources. When WordPress, a plugin, or a theme attempts to use more memory than this configured limit allows, PHP stops execution and displays the memory exhausted error rather than allowing the process to continue indefinitely.
Common Causes of the Error
This error frequently occurs after installing a new plugin or theme that has particularly high memory requirements, during resource-intensive operations like importing large amounts of content, or as a site’s overall complexity grows over time without a corresponding increase in available memory. In some cases, it can also indicate a poorly coded plugin or theme with a memory leak, where memory usage grows unexpectedly rather than being related to a single legitimate resource-intensive task.
Increasing the PHP Memory Limit
The most direct fix involves increasing the memory limit allocated to PHP, which can typically be done by adjusting a specific line in WordPress’s configuration file to define a higher memory limit value. Depending on the hosting environment, this limit may also need to be adjusted at the server level, since some hosts cap the maximum memory limit a site is allowed to request regardless of what’s specified in WordPress’s own configuration.
Adjusting Memory Limits Through Hosting Settings
Many hosting providers, particularly managed WordPress hosts, offer a way to adjust PHP memory limits directly through a hosting control panel rather than requiring a manual configuration file edit. Checking with your specific hosting provider’s documentation or support team is often the fastest way to confirm the correct method for your particular hosting environment.
Identifying the Root Cause Rather Than Just Increasing Memory
While increasing the memory limit often resolves the immediate error, it’s worth investigating what triggered it in the first place, particularly if the error recurs frequently even after an increase. This often means temporarily deactivating recently installed plugins to identify whether one of them is responsible for unusually high memory consumption, rather than assuming the site simply needs progressively more memory indefinitely.
Reviewing Plugin and Theme Quality
If a specific plugin or theme is consistently associated with high memory usage, it’s worth evaluating whether it’s genuinely necessary or whether a better-optimized alternative exists. Poorly coded plugins are a common source of excessive memory consumption, and replacing or removing them often resolves recurring memory issues more effectively than repeatedly increasing the memory limit to accommodate them.
Optimizing Site Performance to Reduce Memory Usage
Beyond addressing specific problematic plugins, general performance optimization, including reducing the number of active plugins, using efficient, well-coded themes, and keeping the database clean, all contribute to lower overall memory usage across the site. A well-optimized site is inherently less likely to encounter memory limit issues in the first place, even under normal, legitimate usage.
When to Involve a Developer
If increasing the memory limit doesn’t resolve the issue, or if the error keeps recurring despite reasonable memory allocations, it’s often a sign of a deeper underlying problem, such as a memory leak in custom code or a poorly optimized plugin, that requires developer investigation rather than a simple configuration change to resolve properly.
Frequently Asked Questions
Is increasing the PHP memory limit always safe?
Generally yes, within reasonable limits, though excessively high memory allocations can mask underlying performance issues that would be better addressed directly, and some hosting environments have practical caps on how high the limit can be set.
Why does the memory limit exhausted error happen after a plugin update?
Plugin updates sometimes introduce new features or dependencies that require more memory to run, which can push a site’s memory usage past a previously sufficient limit, particularly if multiple memory-intensive plugins are active simultaneously.
Can a memory limit be set too high?
While there’s no strict upper limit that causes problems on its own, setting the memory limit excessively high without addressing an underlying cause of high memory usage can allow inefficient code to continue consuming excessive server resources rather than surfacing the issue early.
Does every WordPress site need a high memory limit?
No. Most well-optimized WordPress sites run comfortably within standard memory limits, and needing to significantly increase the limit repeatedly is often a sign that something on the site, whether a plugin, theme, or specific process, deserves closer investigation.
Final Thoughts
The WordPress memory limit exhausted error is usually straightforward to resolve by increasing the allocated memory, but the more valuable long-term fix involves understanding and addressing whatever caused excessive memory usage in the first place. Treating the error as a signal worth investigating, rather than just a quick setting to adjust, leads to a healthier, more stable site overall.
Dealing with recurring memory errors or performance issues on your WordPress site? Talk to our development team about diagnosing and resolving the underlying cause.