Increase the PHP memory limit

If a page stops with this error:

Fatal error: Allowed memory size of 33554432 bytes exhausted

PHP ran out of the memory it is allowed to use. This usually happens while ShopClass resizes a large photo, imports location data, or runs a plugin that works through many rows at once.

The quick fix

Add this line to config.php, above the last lines of the file:

define('OSC_MEMORY_LIMIT', '256M');

ShopClass raises PHP’s limit to this value when it starts. The default is 32M.

Two things to know:

• It changes the limit for ShopClass only. Nothing else on the server changes.
• It only ever raises the limit. If PHP already allows more, ShopClass leaves it alone. So 128M does nothing on a host that already gives you 256M.

When that does not work

OSC_MEMORY_LIMIT uses PHP’s ini_set(), and some hosts block it. Then you must raise the limit where PHP itself is set up. Try these in order.

php.ini, if you can edit it:

memory_limit = 256M

.htaccess, on Apache with mod_php:

php_value memory_limit 256M

On hosts that run PHP-FPM or CGI, this line causes a 500 error. If the site breaks as soon as you add it, remove the line.

Your control panel. cPanel, Plesk and most managed hosts have a “Select PHP version” or “PHP settings” screen with memory_limit on it. This always works, because it changes PHP’s own settings.

Ask your host. On strict shared hosting, this is the only way. Support will usually raise it if you ask.

Checking the current value

In the admin panel, Tools → System info shows the memory limit in use.

How much is enough

Site	Good limit
Small, few photos	64M
Normal classifieds site	128M – 256M
Large imports, big images	512M

A higher limit does not make the site faster. It only lets a runaway process use more memory before PHP stops it. If ordinary pages need far more than 256M, something is wrong. Look for a plugin that loads every row into memory, or for images being resized at their full original size.