I was reading about some php performance tips at work today and decided to throw together some of the ways to make your php site faster.

Here’s a couple of short tips to avoid making your site lag for the user:

Unset your variables. This frees up a surprising amount of memory Use memcache Turn on apache’s mod_deflate If your database is local then close your connections when you’re done with them If your database is remote then use persistant connections Don’t use functions inside of a for loop control expression unless absolutely necessary. Example :

for($i=0;$i<some_big_calculation(20);$i++)

The some_big_calculation function will be called every iteration. Use string concatenation instead of embedding variables in strings.

$some_string = "asdf $asdf2 asdf"; //bad $some_string = 'asdf '.$asdf2.' asdf'; //good When including files, use at least a relative path so PHP doesn’t have to look in the entire path.

include("./some_file.php"); // looks in the current directory include("wrong.php"); // searches every directory in the path Try not to use include_once or require_once. They are more expensive and it really isn’t that hard to only include files once Not everything needs to be an object. There is a fair amount of overhead when doing everything OOP. Use output buffering to make everything seem faster.

Hopefully I didn’t miss any of the big ones.