Maybe this topic needs updating because i have certainly used this in the past, but today adobe illustrator ai files are not uploading.

So I'm using gravity forms plugin to upload my files.

When I tried to initially uploading these file formats...

  1. PSD
  2. EPS
  3. AI
  4. SVG

I was getting this message: Sorry, this file extension is not permitted for security reasons for all of these file formats.

So I filtered my upload mimes by adding this function to my class...

 * my class constructor
public function __construct()

    // allow extra mime type uploads
    add_filter( 'upload_mimes' , array ($this, 'custom_upload_mimes'));


 * Allow extra mime types for the sample upload
 * @return array
public function custom_upload_mimes ( $existing_mimes = [] )

    $existing_mimes['psd']  = 'image/vnd.adobe.photoshop';
    $existing_mimes['eps']  = 'application/postscript';
    $existing_mimes['ai']   = 'application/postscript';
    $existing_mimes['svg']  = 'image/svg+xml';

    return $existing_mimes;


After a bit of testing, all those file types listed above uploaded fine... apart from the illustrator file.

I removed this function and I was not able to upload any of these formats. I re-invoked the function and again, only the illustrator .ai file was returning the error message.

I also tried a very old illustrator file to see if was a file issue but the result was the same.

What should I do to fix this?

2 Answers 2


Please try this:

$mime_types[ 'eps' ] = 'application/postscript';
$mime_types[ 'ai'  ] = 'application/pdf';
$mime_types[ 'svg' ] = 'image/svg+xml';`

and then return $mime_types

  • Thank you let me check soon, i'll get back to you.
    – joshmoto
    Commented Dec 3, 2019 at 6:49

im putting this info here (not about upload) but according to adobe docs the mime types list as following

for .ai is application/postscript

for eps can be any of the following EPS

  1. application/postscript
  2. application/eps
  3. application/x-eps
  4. image/eps
  5. image/x-eps

for psd is image/vnd.adobe.photoshop

for svg is image/svg+xml

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