The default font when composing a page or post using WordPress’s built-in editor is Noto Serif. To change this is very simple and only requires editing one file.
- Use FileZilla or cPanel’s File Manager to navigate to your_website/wp-admin
- Open the file ‘edit-form-blocks.php’ using a text editor (I recommend Notepad++)
- Search for ‘Noto Serif’ and change to your desired font (for me it is located on line 194)
$locale_font_family = esc_html_x( 'Noto Serif', 'CSS Font Family for Editor Font' );
$locale_font_family = esc_html_x( 'Open Sans', 'CSS Font Family for Editor Font' );
It is a good idea to back up the original file in case you accidentally edit the file incorrectly. I would suggest downloading the file to your computer before editing it, so that you can simply re-upload it and replace the file if something goes wrong.
It is worth noting that your chosen font should be one that is installed on your computer already. You should also note that the font chosen here will not affect how the final post/page is displayed on your website to end users; it will only affect how it is displayed to you whilst editing.
Finally, you should note that when an update is installed for WordPress, it is likely that this file will be overwritten and you will need to carry out this change again. It is possible that you may be able to add code to your functions.php file to change the font, but as it’s a fairly straightforward and quick change, I prefer to do it by editing the file.