response time - How long should the delay be before a tooltip pops up?

I'm working on web site in which a "ribbon" submenu pops up as soon as the mouse touches one of the main menu items. I'm trying to explain to the designer that it should wait until the cursor has rested on the menu item, and not pop up when the mouse just happens to pass over it. I'm not sure how long (in milliseconds) that wait should be.

I can't link to the web site in question, but I figure the same principle applies to standard tool tips. How long should it take for a tool tip to pop up?

Answer

If anyone is still looking for updated answers around this subject, Nielsen Norman has a great article on the subject: https://www.nngroup.com/articles/timing-exposing-content/

1. Mouse cursor enters target area: display visual feedback within 0.1 seconds.


2. Wait 0.3–0.5 seconds.


3. If cursor remains stopped within target area, display corresponding hidden content within 0.1 seconds.


4. Keep displaying the exposed content element until the cursor has left the triggering target area or the exposed content for longer than 0.5 seconds.

The 300-500 millisecond pause is to ensure user intent is to see whats behind the menu or tooltip and not mousing by on their way to something else.