<https://neliosoftware.com/blog/how-to-upload-additional-file-types-in-wordpress/>

Mime Type lists

• <https://wpengine.com/support/mime-types-wordpress/>
• <https://www.freeformatter.com/mime-types-list.html>
• <https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types>

## Disallow TIFF/TIF

You MUST unset both tiff and tif otherwise it won’t work.

function my_mime_types($mime_types){
unset($mime_types['tiff|tif']); // Removes the .tiff extension
return $mime_types;
}
add_filter('upload_mimes', 'my_mime_types', 1, 1);
Code language: PHP (php)

Allow csv

// Allow CSV file upload
add_filter( 'upload_mimes', 'my_myme_types', 1, 1 );
function my_myme_types( $mime_types ) {
$mime_types['csv'] = 'text/csv'; // Adds .csv extension
return $mime_types;
}
Code language: PHP (php)

Allow and disallow

add_filter( 'upload_mimes', 'my_myme_types', 1, 1 );
function my_myme_types( $mime_types ) {
$mime_types['svg'] = 'image/svg+xml'; // Adding .svg extension
$mime_types['json'] = 'application/json'; // Adding .json
extension
unset( $mime_types['xls'] ); // Remove .xls extension
unset( $mime_types['xlsx'] ); // Remove .xlsx extension
return $mime_types;
}
Code language: PHP (php)