30-Second Timer
Press start. It counts down to zero and rings an alarm — nothing to download, nothing to sign up for.
About this 30-second timer
A one-click 30-second countdown, most often used for HIIT work and rest intervals, a 30-second pitch rehearsal, or plank and wall-sit holds. It runs in your browser and rings when it reaches zero.
Thirty seconds: the interval-training standard
Thirty seconds is the work or rest block in a huge number of interval workouts, the length of a TV ad slot, and the classic time limit for an elevator pitch. It's also roughly how long the CDC suggests scrubbing hands before rinsing — the advice is at least 20 seconds, and most people fall short.
30 seconds in other units
| Seconds | 30 |
|---|---|
| Minutes | 0.5 |
| Hours | 0.008 |
| Milliseconds | 30,000 |
| Share of a day | 0.03% |
Tips for using a 30-second timer
- For 30/30 intervals, alternate work and rest by restarting the timer — or set a 1-minute timer and switch at the halfway mark.
- Practising a 30-second pitch out loud against a timer is the fastest way to find which sentences to cut.
- Thirty seconds of plank is a reasonable starting target if you're new to core work.
Frequently asked questions
How do I set a 30-second timer?
Press Start above and the page counts down from 30 seconds on its own — nothing to type. Need a little longer? Press +1 min while it runs, or pick a nearby duration from the list.
How many seconds are in 30 seconds?
30 seconds is 30 seconds — 0.5 minutes or 0.008 hours. That's 0.03% of a day.
What is a 30-second timer good for?
People commonly use a 30-second timer for HIIT work and rest intervals, a 30-second pitch rehearsal, or plank and wall-sit holds.
Will it keep time if I switch tabs?
Yes. The countdown is measured against your device clock rather than counting screen refreshes, so it stays accurate in a background tab and the alarm fires on time. Some browsers need one click on the page before they allow sound.