Interval Timer
Free, right in your browser. Set your work, rest, and rounds — or grab a preset — and press start.
Worksec
Restsec
Rounds
Total 05:45
Take it beyond the browser
Zestimer for iPhone and Apple Watch calls every switch with voice and haptics, turns YouTube workouts into timed sessions, and keeps your streak. Free on the App Store.
Interval timer basics
What is a Tabata timer?
Tabata is an interval protocol: 8 rounds of 20 seconds of hard work and 10 seconds of rest — four minutes in total. Tap the Tabata preset above and press start; the timer cues every switch for you.
Will my screen stay awake?
Yes. While the timer runs, this page asks your browser to keep the screen on, so the countdown stays visible through the whole session in most modern browsers.
Is there an app version?
Yes — Zestimer for iPhone and Apple Watch is free. It adds voice cues, taps on the wrist, ready-made workouts, streaks, and can even turn a YouTube workout into a timed session.