PHP Limits

Several of the most confusing WordPress errors are not WordPress errors at all. A media upload that refuses a file, an import that stops halfway, a white screen after installing a plugin — these are usually PHP refusing to go further, because it has hit a limit set by your host.

There are only a handful of limits that matter and each produces a recognisable symptom. Memory, which stops execution with a fatal error naming the byte count. Execution time, which cuts long operations off mid-run. Upload size and post size, which govern what the media library will accept and are often set to different values, so a file passes one and fails the other. Input variables, which silently truncates very large forms — long menus being the classic case.

These guides cover raising each one and, just as usefully, reading the errors so you know which limit you actually hit before changing anything.

There is also the question of where to set them. The same directive can live in php.ini, in .htaccess, in wp-config.php or in your host’s control panel, and they do not all win. One article traces which value actually takes effect.

One is for when nothing you set works, and the answer is to ask your host — with a report that contains what they need and nothing private.