Study Session Timer
25:00
Focusing
Block 1 of 6
The session, phase by phase
- Block 125 min
- Break after block 15 min
- Block 225 min
- Break after block 25 min
- Block 325 min
- Break after block 35 min
- Block 425 min
- Long break after block 415 min
- Block 525 min
- Break after block 55 min
- Block 625 min
The defaults are Francesco Cirillo’s: 25 minutes of work, a 5-minute break, and a longer break after four blocks, from The Pomodoro Technique — self-published in 2006 and reissued by Currency in 2018. They are one person’s working convention that suited a great many other people, not a measured optimum, and there is nothing in the literature that makes 25 minutes the right number for you. Every field above is meant to be changed.
The clock works by subtracting timestamps rather than counting ticks, so it stays correct when a browser throttles a background tab — which every browser does within a minute of the screen dimming. What it cannot do while hidden is make a sound, so keep the page in view if you need to be told the block is over.
Blocks you choose rather than blocks you inherit
Set a length for a block of work, a length for the gap after it, how often a longer rest should fall and how many blocks you mean to sit through. The whole evening is then laid out as a numbered sequence, the clock counts down whichever phase you are currently in, and the summary tells you what time the last block will finish. Every field is adjustable because the right length of a working block is a fact about you and about the material in front of you, not a constant of human attention.
The provenance of twenty-five minutes
Francesco Cirillo worked his method out as an undergraduate in the late 1980s using a tomato-shaped kitchen timer, which is where the Italian word for tomato comes into it. He settled on twenty-five minutes of work, a five-minute gap and a longer rest after every fourth block, described the whole approach in a book first released in 2006 and reissued by Currency in 2018, and still claims the name as a trademark.
Those figures are a working convention that one man arrived at and a great many other people then adopted. No experiment produced them. Twenty-five is not a measured ceiling on concentration, four is not a measured ceiling on stamina, and mistaking either for physiology is where most of the folklore surrounding the method begins. They are offered here as the defaults, credited, and left entirely open to being changed.
Picking lengths that suit the work in front of you
Longer blocks favour tasks with an expensive start-up cost: proofs, essays, debugging, anything where the opening ten minutes go on rebuilding context that you had assembled once already. Shorter blocks favour work you can put down cleanly, and they favour days when beginning at all is the hard part, because a commitment of twelve minutes is a much easier one to make than a commitment of an hour.
The gap has a job as well, and answering messages is not it. Leaving the desk is a different sort of pause from opening another tab, and only one of the two changes what your eyes and your back are doing. If a break reliably turns into forty minutes, that is worth knowing about your own habits before it is worth blaming on the interval you picked.
Why this clock cannot quietly lose time
Pressing start records an instant, and the display is the difference between that instant and the present one. Nothing counts downward. The distinction matters because a phone that dims its screen slows every timer on an inactive page to a small fraction of its intended rate, so a counter built by subtracting one each second comes back several minutes short — always in your favour, always wrong. Subtracting two moments cannot lose anything, however badly the browser behaved while you were not looking. What the page genuinely cannot do while it is hidden is make a sound, so keep it on screen if you want telling.
Twenty-five minutes or fifty
Should I use twenty-five minutes or fifty?
Whichever one you finish. Nobody has measured an optimum that applies to a stranger, so the useful experiment is to run a week of each on the same kind of material and notice which one you abandon less often and which leaves you able to start again the next day.
Why does editing a field stop the clock?
Because moving a boundary underneath a running session would leave the countdown pointing at a phase that no longer exists in the same place. Changing any setting rebuilds the sequence and returns you to the beginning, which is honest about what has actually happened to the plan.
What if I finish a block before the timer does?
Use the skip control, which jumps to the end of the phase you are in and moves straight on to the next one. The plan below the clock keeps its original shape, so the session still finishes with the number of blocks you asked for rather than losing one.
Can I run it with no breaks at all?
Yes. Set both break fields to zero and the session becomes an unbroken stretch divided into numbered blocks, which some people prefer for exam-style practice where the point is to sustain attention for the length of a real paper rather than to rehearse stopping.