Is there any way to prevent WordPress from cropping files based on their file extension. Actually, I want to disable cropping for GIF files because after cropping GIF image...

  1. GiF image does not remain animated
  2. Even it does remain animated, I will not be using those small GIF sizes.

So is there any way to disable thumbnail generation (for GIF) based on what file extension a image have.

  • Why not just use the original files in your theme/posts and not the thumbnails? Sep 24, 2014 at 11:11
  • What? How would I do that?
    – Robert hue
    Sep 24, 2014 at 11:12
  • Wordpress creates different sizes of your image, but it doesn't remove the original file. How / where are you using your gif files? Sep 24, 2014 at 11:14
  • That's the question. I am using original GIF in website/theme but all other sizes are useless for GIF images. So I want to disable generating thumbnails for GIF images.
    – Robert hue
    Sep 24, 2014 at 11:16
  • Okay. I see your point. I am just wondering if there is really a need to achieve this other than that. Gif files take minimal space on server, so I wouldn't waste a lot of time to achieve something that doesn't really effect the server nor your site. I will get back to you if I actually have an answer to your original question. Sep 24, 2014 at 11:20

1 Answer 1


Unsetting sizes can normally be done easily via intermediate_image_sizes_advanced hook. The only problem is, there is only the $sizes array available, so this sufficient for a general level, but not if you want to do this conditionally. The information needed to do it conditionally can be gathered with debug_backtrace - debug_backtrace is performance-wise somewhat expensive though. Anyhow, I imagine it could be done like shown below:

function wpse162413_unset_sizes_if_gif( $sizes ) {
    // we're only having the sizes available
    // we're using debug_backtrace to get additional information
    $dbg_back = debug_backtrace();
    // scan $dbg_back array for function and get $args
    foreach ( $dbg_back as $sub ) {
        if ( $sub[ 'function'] == 'wp_generate_attachment_metadata' ) {
            $args = $sub[ 'args' ]; 
    // attachment id
    $att_id       = $args[0];
    // attachment path
    $att_path     = $args[1];
    // split up file information
    $pathinfo = pathinfo( $att_path );
    // if extension is gif unset sizes
    if ( $pathinfo[ 'extension' ] == 'gif' ) {
        // get all intermediate sizes
        $intermediate_image_sizes = get_intermediate_image_sizes();
        // loop trough the intermediate sizes array
        foreach ( $intermediate_image_sizes as $size ) {
            // unset the size in the sizes array
            unset( $sizes[ $size ] );
    // return sizes
    return $sizes;
  • sorry I could not test it earlier. Just tested this functions and YES it seems to be working exactly like I require. You are awesome. Thanks a lot.
    – Robert hue
    Sep 27, 2014 at 6:14
  • You said debug_backtrace is expensive for performance but since we will be uploading files from backend only then should it make any effect on overall website performance?
    – Robert hue
    Sep 27, 2014 at 6:15
  • 1
    My pleasure, it's always nice if something actually works :) About the performance, I just add that as additional information, most likely it's fine, but you could have a site with a lot of users and all of them are sharing gif pics like crazy...you get the point. @Roberthue Sep 27, 2014 at 6:37
  • That's great! I think it should not slow down my website because I have 5 users and they will be uploading maximum of 20-30 GIF images in 24 hours.
    – Robert hue
    Sep 27, 2014 at 6:44

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