20 Second Timer
Counts down 20 seconds in your browser and sounds an alarm when it finishes. No sign-up, no ads.
00:00:20
20 seconds
- Washing your hands — 20 seconds is the length public-health guidance asks for
- A plank or wall-sit hold
- Letting a screen protector settle
This is a ready-to-go 20 second timer: press start and it counts down from 00:00:20, then plays an alarm. Nothing is sent anywhere — the countdown and the alarm both run in your browser, so it keeps working with no connection.
What people set 20 seconds for: washing your hands — 20 seconds is the length public-health guidance asks for, a plank or wall-sit hold, letting a screen protector settle. The 20-second handwashing guideline is why this is the most-set sub-minute duration; it is roughly two rounds of "Happy Birthday".
Need a different length, laps, or a sequence of intervals back to back? The full stopwatch and timer takes any duration, records lap times, and runs multi-step interval workouts.
How long is a 20 second timer?
20 seconds. The countdown on this page starts at 00:00:20 and runs to zero.
What is a 20 second timer used for?
Most often: washing your hands — 20 seconds is the length public-health guidance asks for, a plank or wall-sit hold, letting a screen protector settle. The 20-second handwashing guideline is why this is the most-set sub-minute duration; it is roughly two rounds of "Happy Birthday".
Does the 20 second timer keep running if I switch tabs?
The elapsed time is measured against the clock rather than counted frame by frame, so the total is unaffected by a background tab — it catches up the moment the tab is visible again. Browsers do throttle background tabs, though, so the alarm can be late if the timer finishes while the tab is hidden. Closing the tab stops it entirely; for anything longer than an hour a phone alarm is more reliable.
Does it work offline?
Yes. The page is cached the first time you visit, and the timer and its alarm are entirely local — nothing is sent to a server and there is no account to create.