I am working with WordPress 3.3.1 and cannot resize the image I am trying to add to the page as the thumbnail, small, medium and large options are greyed out. the size of the image in question is 276x354.

I have created my own theme and have added <?php the_post_thumbnail(); ?> template tag but to no avail. Does deactivating the visual editor have anything to do with this.

I have not come across this problem before and would appreciate any pointers on what could be causing this problem.

Thanks in advance. nav

  • did u define the image sizes on functions.php? Commented Feb 12, 2012 at 16:47
  • No I did not I am just using the defaults. The interesting thing is that two identical install of WordPress are behaving differently. One greys out the image size options and the other does not. Any reasons?
    – nandac
    Commented Feb 12, 2012 at 17:03
  • identical installs with the same theme ?
    – krembo99
    Commented Feb 12, 2012 at 18:34

3 Answers 3


it can be caused by multiple reasons , some of which may be :

  • theme disabling this function

=> switch to default theme and check function again

  • GD library not installed on server

=> check your PHP server settings .

  • the image you are inserting is smaller than the thumbnail image size set in Admin/Settings/Media.

=> check your default image sizes and / or upload a bigger image

  • some plugin is causing it

=> disable all plugins and check function again.

  • Defected image

=> Try another image

  • Max file upload restriction

=> In functions.php

 @ini_set( 'upload_max_size' , '64M' );
@ini_set( 'post_max_size', '64M');
@ini_set( 'max_execution_time', '300' );
  • I did not have the php5-gd package installed on the installation that could not resize the image after further investigation. Thanks for the info.
    – nandac
    Commented Feb 13, 2012 at 4:15

Maybe you have to add thumbnails support via functions.php

if ( function_exists( 'add_theme_support' ) ) { // WP 2.9+
    add_theme_support( 'post-thumbnails' );
    set_post_thumbnail_size( 220, 150, true ); //you can set featured image size
    add_image_size('custom_size', 950, 325, true);  //or add new support sizes

to get big_image size try:

the_post_thumbnail( 'custom_size' );
  • A check for function_exists( 'add_theme_support' ) is not necessary anymore.
    – fuxia
    Commented Feb 13, 2012 at 11:22

well basically if you uploaded a file that's 276x354 than wordspress wont make those other sized options since the image is already small.

if you want to get those sizes you need to add support for it in you functions.php file, and then upload again, or use a regenerate thumbnails plugin/code.

i also suggest you install an image resizing plugin, like Scissors 2, so you can make actual changes to the files you upload.

does this help?

  • Actually it does create smaller and larger images with the image mentioned above but I have read that an image already small will not get resized in WP.
    – nandac
    Commented Feb 13, 2012 at 4:17

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