Frequently Asked Questions

A HIIT (High-Intensity Interval Training) timer alternates short bursts of intense work with rest periods, signalling each switch so you can focus on the workout instead of watching a clock.

Set your work and rest durations and the number of rounds, press start, and the timer counts down each interval, plays an audio cue at every switch, and tracks your progress through the session — hands-free.

Yes, it's completely free with no sign-up, downloads, or limits. Use it for as many workouts as you like.

Yes. You can set your own work and rest durations in seconds, the number of rounds per set, and the number of sets — or use a built-in preset like Tabata (20 seconds work, 10 seconds rest, 8 rounds).

Yes. The timer uses the Web Audio API so cues sound reliably even when the screen is locked or the tab is in the background.

On supported browsers the timer uses a screen wake lock to keep the display awake so your session isn't interrupted. On browsers that don't support it, the timer still runs and the audio cues still play.

Yes. You can start, pause, resume, and reset at any time. The timer picks up exactly where you left off when you resume.

No. The timer runs entirely in your browser and doesn't store or send any personal data to a server.

Yes, the timer is fully responsive and designed for use on a phone during a workout, as well as on tablets and desktops, with the display fitting the screen without overflow.

HIIT is intense by design. It's popular and effective, but the right intensity depends on your fitness and health. If you're new to exercise or have any health condition, check with a doctor before starting — this tool is a timer, not medical advice.