Interval Timer (Tabata, HIIT)

An interval timer for Tabata, HIIT, EMOM and circuits: work, rest, rounds, sets and cool down, with beeps at every change. Keeps time in a background tab.

Timer

Get ready

00:10

  1. Get ready10 s
  2. Work · round 120 s
  3. Rest10 s
  4. Work · round 220 s
  5. Rest10 s
  6. Work · round 320 s
  7. Rest10 s
  8. Work · round 420 s
  9. Rest10 s
  10. Work · round 520 s
  11. Rest10 s
  12. Work · round 620 s
  13. Rest10 s
  14. Work · round 720 s
  15. Rest10 s
  16. Work · round 820 s

Total 4 min

Workout

s
s
s
s

A short beep starts each work phase, a lower one each rest, and four mark the end. Changing a setting starts again.

How is this calculated?
Total = get ready + sets × (rounds × work + (rounds − 1) × rest) + (sets − 1) × rest between sets + cool down. No rest is added after the last round of a set.

Runs in your browser — nothing you enter leaves this device.

About this tool

What it does

Interval Timer runs workouts made of repeated work and rest periods. Set how long to get ready, how long each work and rest period lasts, how many rounds make a set, how many sets, the rest between sets and a cool down, and the timer lists every phase and runs through them, beeping at each change: two high beeps when work starts, three lower ones for rest, and four at the end. Presets fill in common formats: Tabata (20 seconds of work and 10 of rest, eight times — the protocol studied by Izumi Tabata), HIIT at 40/20 for ten rounds, EMOM (a new round every minute for ten minutes), and a three-set circuit with longer rests between sets. The current phase is shown large and coloured — warm for work, green for rest — so it can be read from across a room, and the time left also shows in the tab title. It keeps time from the clock, so it stays accurate in a background tab.

How to use it
  1. Pick a preset or set the work, rest, rounds and sets yourself.
  2. Check the phase list and the total time.
  3. Press Start; Pause, Skip or Reset at any time.
  4. Follow the beeps and the colours: warm for work, green for rest.
Limits and your data
  • Keep the page open and the device unlocked for the beeps; phones may silence web pages when the screen is locked.
  • Changing any setting starts the workout again.
  • This times the workout; it does not count repetitions or measure heart rate.
  • Check with a doctor before starting high-intensity training if you have a heart condition or have not exercised for a while.
  • The workout settings and the running timer stay on this device; nothing is sent.

Questions

What is a Tabata workout?

Eight rounds of 20 seconds of all-out effort and 10 seconds of rest, four minutes in all. Choose the Tabata preset.

What is EMOM?

Every Minute On the Minute: start a set number of repetitions at the top of each minute and rest for what remains. The EMOM preset runs ten one-minute rounds.

Can I do several sets with a longer rest between them?

Yes. Set Sets above 1 and the “Rest between sets” appears; the circuit preset shows it.

Does it keep time if I switch apps?

Yes in a background tab: it reads the clock rather than counting. A phone may pause sound while the screen is off.