Relying on the title attribute is currently discouraged as many user agents do not expose the attribute in an accessible manner as required by this specification (e.g., requiring a pointing device such as a mouse to cause a tooltip to appear, which excludes keyboard-only users and touch-only users, such as anyone with a modern phone or tablet).
Title-attribute
This page is about the title attribute, not the <title>-element.
Use title-attributes
In frames and iframes for a descriptive
Don't use title-attributes
On all other elements.
- Title text might overlap content unwantedly
- Title text does not resize when zoomed in
- Title text might be read by sreenreaders or might not be read by screenreaders
- Title text is only shown via mouseOver; users on touch devices won't see the text
- And for SEO reasons you will better score on great link texts than on title texts
Sources