Increase PHP Memory Allowance Using ini_set()

By  on  

On rare occasion, I need to up the memory allowed for PHP. Usually it's when I deal with large files and don't necessarily care about optimizing the file reading process but simply getting the file opened. There's an easy way to increase to amount of memory allowed to PHP right in your script:


The above code will increase the maximum amount of memory available to PHP to 16 MB. Again, the setting is only adjusted for the running script.

Track.js Error Reporting

Upcoming Events

Recent Features

  • I’m an Impostor

    This is the hardest thing I've ever had to write, much less admit to myself.  I've written resignation letters from jobs I've loved, I've ended relationships, I've failed at a host of tasks, and let myself down in my life.  All of those feelings were very...

  • CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

Incredible Demos

  • Sara Soueidan’s Favorite CodePen Demos

    A few months ago, Chris Coyier shared his favorite CodePen demos right here on David's blog. A while back David asked me to share some of my favorite pens too, so here are some of the demos that have blown my mind in the past...

  • CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...


  1. chuck

    I had to do this recently for a client who had joomla (yuck) installed. I just posted this in the top of their main index.php file so it was loaded on every page. It’s really good as a quickfix if you’re using something like Gallery or Joomla along with php-cgi, since php-cgi doesnt let you use htaccess.

  2. Thank you o-b-wan, both for this post, and the kindly remonstration given on the other post that sent me here.



  3. This worked great David.

    I had to place it below some other “session_start();” code in the index2.php file of a troublesome joomla installation, but it worked just as you offered.

    memory_limit Local 16M; Master 8M

    Thanks again o-b-wan.

    Off to look for the next pebble…


  4. Sam

    I have a problem with wordpress installing plugins where I get the error:

    Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 122880 bytes) in /var/virtual/web/w1032/html/wp-content/plugins/wp-postratings/wp-postratings.php on line 872

    Which file should I place the code in? And I obviously need to increase it past 16MB so can I just put in:


    maybe wp-config.php or the actual plugin? wp-postrating.php?

  5. Sam

    I cannot install plugins on wordpress due to a memory error.

    I can’t get to php.ini, which file do you know should I put



    wp-config, the plugin script or all the wp php files?


  6. Akshay

    @Sam: You have to put


    this line of code in the file/page, which on calling gives the error.

  7. Tob-e

    I’ve got a strange behaviour on PHP 5.2.11.
    The php.ini set the memory_limit to 128MB. I can adjust the limit to 64M but never above the limit of 128M.

    Did someone noticed a similar problem?

  8. I tried to install wordpress 3.0.1 and i received this message : Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2966269 bytes) in /home/blidaru/public_html/wp-includes/http.php on line 1364

    What i have to do?

    • put this on top of your http.php file


      if that didn’t worked out try increasing 32M until it works for you

  9. ini_set('memory_limit', '-1'); will be a neat solution as well. but I am still not sure of any side effects of this!

    • Chasalin


      If you happen to have any flaw in your code, this could cause your server to become unresponsive.

      Setting the memory_limit to -1 (infinite) should only be done for testing purposes on non-production machines!

  10. Life saver, as always David.

    Host of my dedicated saw fit to lower all max memory across their entire network for “security reasons”. Screw em, Big Daddy Walsh has my answer!

    • Blgr3

      Tried, didn’t work…

  11. Thanks David but it didn’t work in my case – I think my host has put a limit on memory access – had an image resizing script with imagecreatetruecolor() – and script just would not go past it.

  12. gaurav



  13. berk

    Here are 3 ways on how to increase it

  14. I need to put this in php.ini file or .htaccess file ?

  15. @samily .htaccess is important in main folder (public_html) not in php.ini

  16. Sanjiv

    Great works I just added and it works.

  17. Egon_Freeman

    Just so you know, the administrator CAN limit your ability to increase this limit! There’s such a thing called PHP Safe Mode, and in this mode you can set function calls that will NOT be executed, no matter who calls them or from where. One of these functions can be ini_set(), which would block it completely.

    You can also try setting it via .htaccess, but that doesn’t always work (it hinges on ALLOW OVERRIDES being set to something other than NONE, I believe).

    Keep that in mind. Sometimes, the only valid solution is to change your host.

  18. Hi David,

    I’m trying this right now. Somehow from php.ini it’s already 512M. In wp_config.php I also put define('WP_MEMORY_LIMIT', '512M'); but somehow it keep getting 256M.

    I decided to use the ini_set('memory_limit','1024M'); in my php file to see if it has any improvement. So far it’s not breaking due to memory limit yet.

    So thank very much for pointing this out.

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!