Interval Timer — Free HIIT and Tabata Timer

Setting up a session

Set the work period, the rest period, and how many rounds you want. The lead-in gives you time to get into position before the first work interval starts. The line under the clock shows the arithmetic and the total, so you know what you are committing to before you press start. Each transition is announced out loud and preceded by three countdown beeps, which is the part that matters — you should not have to look at a screen mid-effort.

Tabata and the common protocols

Tabata is 20 seconds of work and 10 seconds of rest for 8 rounds, four minutes in total, and it is meant to be done at genuinely maximal intensity — it comes from Izumi Tabata's 1996 research on Olympic speed skaters, not from a general fitness plan. The more common gym protocols are gentler: 30 on and 30 off, 40 on and 20 off, or a minute of work to a minute of rest. Set whichever you actually use rather than accepting a default.

Circuits and EMOM

For a circuit with several stations, set the work interval to your station time and the rest to your changeover time, with rounds equal to the number of stations times the laps. For EMOM — every minute on the minute — set work to 60 seconds and rest to zero, and treat whatever time you have left after finishing the reps as your recovery.

It keeps time in the background

The countdown is calculated from a fixed end time rather than a frame counter, so it stays accurate if you switch apps or the screen dims. On phones the display is kept awake while a session is running. That said, put the phone somewhere you can hear it rather than relying on watching it.

Common questions

What is the standard Tabata timing?

Twenty seconds of work, ten seconds of rest, eight rounds — four minutes total. Set work to 20, rest to 10 and rounds to 8.

Will it keep running if my screen turns off?

The timing stays correct, and on phones the page asks the system to keep the screen awake while a session runs. Audio may be delayed slightly if the device fully sleeps.

Can I have no rest between rounds?

Set rest to 1 second for a continuous session with an audible round marker. For true EMOM work, use a 60-second work interval and no rest.

Why does it beep before the interval ends?

Three countdown beeps before every transition, so you can prepare for the change without watching the screen.

Why is the total less than rounds multiplied by work plus rest?

Because the session ends on a work interval — there is no rest after the final round. Eight rounds of 20 seconds work and 10 seconds rest is eight work intervals but only seven rests: 8 x 20 + 7 x 10 = 230 seconds, not 240. The breakdown under the clock shows this.