Don’t use the title attribute for anything important
In older versions of WordPress titles would show on hover, after a lag. They may, or may not, get read by screen readers. Now they are just the title of the image. Depending on the theme and its functions the title added in the attachment details may or may not show up.
There’s a different way to add the title that shows up on hover.
Do not use the
title
attribute, on any element, for any text that you want all users to have access to.Only use it to label a form control when the same text is provided as visible text.
Do not use it on a link to provide information that may be important to any user.
The Paciello Group
The title that shows up on hover
It’s still possible to get a title that shows on hover. This title is added in the block editor, under “Advanced”.

Hover over the iguana. After a small lag you’ll see text that says, “Don’t put anything important here”. If you’re using a screen reader you may or may not hear anything.
