Interval Timer
Free online interval timer for HIIT, Tabata, circuits and EMOM — beep cues, presets and rounds, hands-free.
Configure intervals
Tip: 0 seconds disables a phase. Beeps cue every phase change and count down the last 3 seconds of each work phase.
Quick Answer
An interval timer alternates timed work and rest phases for a set number of rounds — the standard tool for HIIT, Tabata, circuit training and EMOM workouts. Set your work seconds, rest seconds and rounds (plus optional warm-up, sets and cooldown), press start, and the timer calls each phase change with a beep and counts down the last three seconds of every work interval so you never have to watch the clock. Presets for Tabata (20/10 × 8), HIIT 30/30, EMOM and more are one tap away, and the tab title keeps ticking if you switch windows. It runs entirely in your browser — free, with no app install.
How It Works
Tap a preset like Tabata or HIIT 30/30, or enter your own work, rest, rounds and sets
Click anywhere once to enable the beep cues, then press Start workout
Follow the color-coded phases — beeps call every change and count down the last 3 seconds of work
Key Facts
- Configurable work, rest, rounds, sets, warm-up, set break and cooldown — 0 disables a phase
- One-tap presets: Tabata 20/10 ×8, HIIT 30/30, HIIT 40/20, EMOM, 7-minute workout, circuit training
- Beep cues announce every phase change and count down the final 3 seconds of each work interval
- Color-coded phases: red for work, green for rest, blue for set breaks, amber for warm-up
- The browser tab title keeps counting even when you switch windows or lock your phone screen orientation
- Drift-free: phases are computed from real clock timestamps, so a throttled tab never loses time
- 100% client-side — free, no account, no app, works offline once loaded
Frequently Asked Questions
How do I use the interval timer for Tabata?
Tap the "Tabata" preset — it loads the classic protocol: 20 seconds of all-out work, 10 seconds of rest, repeated for 8 rounds (4 minutes total). Press Start, place your phone where you can hear it, and train. The timer beeps twice when work begins, counts down the last 3 seconds, and beeps once when rest begins.
What is the difference between rounds and sets?
Rounds are the number of work/rest repetitions inside one circuit; sets are how many times the whole circuit repeats. For example 3 sets × 5 rounds of 45s work / 15s rest with a 60-second set break gives you three passes through the circuit with a longer breather between passes. Set the set break to 0 if you only want one set.
Will the alarm still work if I switch tabs or turn off my screen?
Beeps are driven by real clock timestamps rather than counted ticks, so the timing stays correct even in a throttled background tab, and the tab title shows the live countdown while you work in other windows. On phones, fully closing the browser or force-stopping the tab will stop the audio, so keep the tab open during your workout.
Can I use it for purposes other than HIIT workouts?
Yes. Any alternating timed routine works: study sprints (Pomodoro-style 25/5), stretching, boxing rounds, meditation, presentations, tabata-style cleaning bursts, or interval running. The phase labels stay generic (Work/Rest), and disabling warm-up or cooldown by setting them to 0 keeps things simple.
Does the timer need an internet connection?
No. Once the page has loaded, the timer, beeps and presets all run locally in your browser. There is no account, no upload and no server round-trip — the workout works in airplane mode, in a gym with poor signal, or on a tablet in airplane mode.
How loud are the beeps and can I change them?
Cues are synthesized with the Web Audio API at a fixed comfortable volume — two short high beeps signal work, one low beep signals rest, and single ticks count down the last 3 seconds of work. Browser autoplay rules require one click or keypress on the page before audio can start; the timer shows a reminder until sound is armed.