Using WOFF & WOFF2 together means your font will be almost universally supported by browsers so take your old TTF files and convert them using CloudConvert.

Find the wp-content/themes/Divi/includes/builder/core.php file in your website’s file system. Download a backup copy to your computer just in case.

Open the core.php file and search for this function:

function et_pb_get_supported_font_formats() { return apply_filters('et_pb_supported_font_formats', array('ttf', 'otf')); }

Divi uses this function when uploading new fonts. As you can see it is currently set to only allow OTF and TTF fonts.

Add the WOFF and WOFF2 formats to the array and save the file. It should look something like this:

function et_pb_get_supported_font_formats() { return apply_filters('et_pb_supported_font_formats', array('ttf', 'otf', 'woff', 'woff2')); }

Now go back into the Divi Builder and upload the fonts in the normal way. Make sure you select the WOFF file and the WOFF2 file when you upload them.

Your WOFF fonts should now be uploaded and working so save and exit the Divi Builder.

Find the core.php file and remove WOFF and WOFF2 items from the array and save it so it looks like this again:

function et_pb_get_supported_font_formats() { return apply_filters('et_pb_supported_font_formats', array('ttf', 'otf')); }