4 hours
The 4-hour timer counts down exactly to zero and immediately shows the equivalent of 4 hours in minutes and seconds. The interface is simple: the Start, Pause, and Reset buttons respond instantly. Full-screen mode is activated with a single tap, and the end notification sound can be easily adjusted by volume or turned off.
The tag works correctly on smartphones, tablets, and desktops. Even when you switch to another tab, the timer doesn't break, and the remaining time is displayed in the page title.