Using the 20 seconds timer
The timer is already set to 20 seconds. Start it with the button, the space bar or a tap on the display; pause with the same. +1 min extends it while it runs, and Reset puts it back to 20 seconds. Turn on Restart automatically to repeat every 20 seconds, or change the hours, minutes and seconds for a different length.
The time left shows in the browser tab, so you can switch to another tab and still see it. Leave the tab open and your device awake for the alarm to sound.
Other lengths
Questions
How do I set a 20 seconds timer?
This page is already set to 20 seconds. Press Start or the space bar and the alarm sounds when it reaches zero.
Can I repeat the 20 seconds timer?
Turn on Restart automatically and the timer begins another 20 seconds as soon as the alarm sounds.
Will it keep counting if I switch tabs?
Yes. The countdown is based on the end time, so switching tabs or reloading doesn't change it. Keep the tab open for the alarm.