HIIT timer
Pick a preset such as Tabata or set your own intervals, then press Start. Three beeps count down the end of every phase.
Sealed on this device
Runs in your browser. Nothing is uploaded.
Sealed
Interval timer
Ready
04:00
Press Start when you’re ready
- Next
- Total left
- 04:00
Presets
Your workout
- Total time
- 04:00
- Time working
- 02:40
This workout would last more than 99 hours. Lower the rounds, the sets or the times.
Timing follows your device’s clock, so it stays exact in a background tab. Keep this page open until the end.
How it works
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Choose your intervals
Pick Tabata, 30/30, 40/20 or EMOM, or set the warm-up, work, rest, rounds, sets and cool-down yourself. The total time updates as you type.
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Start and read the phase
Press Start or Space. The current phase is written in large letters, work on solid ink and rest on a light background, so you can read it from across the room.
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Follow the beeps
Three short beeps count down the end of every phase and a longer tone marks the change. A chime rings when the workout is over.
Frequently asked questions
What is a Tabata workout?
Tabata is 8 rounds of 20 seconds of very hard effort, each followed by 10 seconds of rest. It comes from a 1996 study led by Izumi Tabata (Medicine & Science in Sports & Exercise), in which young, active students pedalled on an exercise bike at a very high intensity. Here the rest after the last round is skipped, since the workout ends there, so the Tabata preset lasts 3 minutes 50 seconds after a 10-second warm-up.
How do I set up my own intervals?
Change any field: warm-up, work, rest, number of rounds, number of sets, rest between sets and cool-down. A set is a series of rounds; between two sets, the longer rest between sets replaces the usual rest. A time set to 0:00 is simply left out. Your last settings are remembered on this device only, and nothing is sent anywhere.
Does the timer stay on time in a background tab?
Yes. Each phase is worked out from your device’s clock rather than by counting ticks, and the beeps are scheduled ahead, so the timing stays exact when you switch tabs. Keep the page open: closing or reloading it stops the workout. Some phones pause web pages when the screen locks, which is what “Keep the screen on” prevents.
Why can’t I hear the beeps?
Browsers only let a page play sound after you have tapped or pressed a key on it, which pressing Start does. Check that “Beep before each change” is ticked and that your device isn’t muted; on an iPhone, the silent switch also mutes web pages. Use “Test the sound” to check the volume. The beeps are generated in your browser, so there is no file to download.
What does EMOM mean?
EMOM stands for “every minute on the minute”. A new round starts at the top of every minute: you do your repetitions, then rest for whatever is left of that minute. The EMOM preset runs 10 one-minute rounds with no separate rest, and the beeps mark the start of each minute.
Is high-intensity interval training right for me?
Hard intervals put a real load on the heart and joints. If you have a heart or blood pressure condition, are pregnant, are recovering from an injury or haven’t exercised for a long time, ask a doctor or a qualified coach first. Warm up before the hard rounds, and stop at once if you feel chest pain, dizziness or unusual breathlessness. This timer only keeps time; it gives no medical or training advice.