Does it keep running in the background?

It runs while the tab is open; background tabs may throttle timers.

Not yet — the display reaches zero when time is up.

Countdown Timer

Set a countdown timer with start, pause and reset.

05:00

MinSec

Count down from any duration. Start, pause and reset as needed — runs entirely in your browser tab.

Does it keep running in the background?: It runs while the tab is open; background tabs may throttle timers.
Is there a sound?: Not yet — the display reaches zero when time is up.