How to increase WordPress migrate plugin import size

Go ahead and open up /wp-content/plugins/all-in-one-wp-migration/constants.php

Find these lines:

// =================
// = Max File Size =
// =================
define( 'AI1WM_MAX_FILE_SIZE', 536870912 );

You’ll see the max size is defined in Bytes. In order to increase the upload size limit, simply add the number you need.