Placeholder text normally isn't used as:
- it vanishes when the user starts typing, which can cause problems for users with memory conditions or when reviewing answers
- not all screen readers read it out
- its browser default styles often do not meet minimum contrast requirements.
Tooltips should never be used as:
- the user must click on the question mark icon and then a small pop-up window displays that's hard to read
- if the user doesn't notice the small icon, they can miss important information.
- forcing the user to hover with a mouse is inaccessible, as it requires fine motor skills
- touch screens can't hover, so people on smartphones or tablets can't get the information
- not all screen readers will read out the tooltip text
- screen magnifiers move the user's field of view, which hides the tooltip
- users can’t select or interact with any content in the tooltip
