gizmobench

Interval Timer

Set a work interval, a rest interval and a number of rounds, add a warm up or a cool down if you want them, and the whole sequence appears as a strip under the clock so you can see what is coming and jump to any interval in it. Two things here are not the page-one norm. The count is read off your system clock rather than added up tick by tick, which is the failure most browser timers have: a hidden tab has its timers slowed to about one a minute, so a counter quietly runs slow, while this one works out where you are from the time that has actually passed and is already right the moment you look back at it. And the whole session is counted, not only the interval you are in, with the last rest included, so eight rounds of 20 and 10 read 4:00 rather than 3:50. Timings are typed in seconds or as minutes and seconds, the plan can be copied as text, nothing is uploaded, there is no account, and the numbers you settle on stay in this browser.

Warm up00:100:10 warm up, 8 rounds of 30 s work and 15 s rest. Total 6:10, the last rest counted.
s
s
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Total
6:10

Ready. Press Start to begin the first interval.

  • Tabata pattern20 on, 10 off, 8 rounds
    4:00
  • 45 on, 15 off8 rounds with a minute either side
    11:00
  • One minute rounds60 on, no rest, 10 rounds
    10:00

A round is one work interval followed by one rest interval, and the last rest is counted like every other one, which is why eight rounds of 20 and 10 come to 4:00 rather than 3:50. Type seconds, or minutes and seconds as 1:30. Skip moves to the next interval and any interval in the strip can be jumped to. Tabata is the name of a timing pattern, 20 seconds on and 10 off for eight rounds, and that is all this page means by it.

Exact about elapsed time. Exact to the timestamps your browser reports, so it does not drift while the tab is in the background. It is a timer and nothing else: the tabata pattern is a named timing pattern, not an exercise prescription.

Common questions

Does the timer keep counting if I switch tabs or lock my phone?
The count does. Browsers stop drawing a hidden tab and slow its timers to roughly one a minute, so a timer that adds a second to a counter every second loses whatever the browser did not deliver and comes back short. This one keeps the clock reading it started from and subtracts, so the interval you are in is worked out from elapsed time and nothing is ever accumulated: leave the tab for two minutes and the first reading after you return is exactly right. The sound is the part that cannot be promised. A throttled tab can deliver a cue late, a device that has gone to sleep may not deliver it until you wake it, and closing the tab ends the session, because nothing here runs outside the page.
Why does a tabata set come to 4:00 and not 3:50?
Because the last rest is part of the pattern and this page counts it. Eight rounds of 20 seconds of work and 10 seconds of rest is eight twenties plus eight tens, which is 240 seconds, or 4:00. Timers that stop after the eighth work interval show 3:50 and disagree with every stopwatch in the room. The final rest is a step in the sequence strip like every other one, so you can see it sitting there before you start.
What does the Tabata pattern button set, and can I change the timings afterwards?
It sets 20 seconds of work, 10 seconds of rest and 8 rounds, with no warm up and no cool down, which comes to 4:00. Tabata is the name of a timing pattern and that is all this page means by it: the timer states intervals and rounds and never tells you what to do inside one. Every number stays an ordinary editable field after the pattern lands, so you can make it 30 and 15, or add a minute of warm up, and the sequence and the total are worked out again as you type.
Can I have a warm up, a cool down, or rounds with no rest at all?
Yes to all three. A warm up or a cool down of 0 leaves that interval out of the sequence entirely rather than showing an empty step, and a rest of 0 gives you back to back work intervals, which is how a one minute rounds session is set up. The work interval is the one value that cannot be 0, because a round has to have something in it. Timings are typed in seconds, or as minutes and seconds like 1:30, and a value that cannot be read is refused with a message naming the field rather than quietly turned into something near it.
Do I need an account or an app, and is the sound optional?
No account, no install, and nothing about your session leaves the page. The cue is a short tone the page synthesises with Web Audio rather than a file it downloads, so it also works with no network, and the Cue button turns it off. One browser rule applies to every site: there has to be a click on the page before any sound can play, which is what pressing Start provides.
Are my timings remembered, and how do I move around the sequence?
The five timings and the cue switch are kept in this browser only, and the Start over button at the top of the page forgets them. Skip moves to the start of the next interval, Restart goes back to the beginning of the first one, and any interval in the strip can be jumped to by clicking or tabbing to it. Moving about changes the elapsed time rather than a counter, so the reading stays exact wherever you land. Copy plan puts the whole sequence on the clipboard as text, one line per interval with the time it starts and the time it ends.

Exact to the timestamps your browser reports, so it does not drift while the tab is in the background. It is a timer and nothing else: the tabata pattern is a named timing pattern, not an exercise prescription.