Now, if you're using the Classic editor, you'll get a larger and resizeable box for entering alt text.
Because the text entry uses
<textarea> most browsers will also show any spelling errors. Good spelling is essential for people who use text-to-speech to read out alt text.
Huge thanks to the WordPress team for doing all the hard work to make sure this works properly. I hope this will encourage people to write longer and more useful alt text.