30 minutes timer

What a 30-minute timer is good for

Half an hour is a fundamental unit of the working day and a satisfying block of focused time. It is the length of a standard meeting slot, a TV episode, a solid workout, and the long break at the end of a set of Pomodoros. Thirty minutes is long enough to finish something substantial and short enough that you stay engaged the whole way through.

• •Time-boxing a meeting to a strict half-hour slot
• •A complete workout, run, or exercise class
• •The long break after four Pomodoro work intervals
• •A focused deep-work block on a single deliverable
• •Oven-cooking and baking that runs around thirty minutes

Time-boxing: why a hard 30-minute limit makes you faster

Time-boxing is the practice of giving a task a fixed, non-negotiable slot rather than working on it until it is 'done'. It works because of Parkinson's Law: work expands to fill the time available for its completion. A report that could be drafted in thirty focused minutes will somehow take all afternoon if you give it all afternoon, because without a deadline you polish, second-guess, and drift. A hard thirty-minute box forces prioritisation, you do the most important eighty percent and accept that the last twenty percent of polish was never worth the disproportionate time it costs. Meetings are the clearest example: a thirty-minute calendar slot that everyone treats as a real limit produces tighter agendas and faster decisions than an open-ended hour. The timer is what makes the box real; a deadline you can quietly extend is not a deadline at all.

How this 30-minute timer stays accurate

Most browser timers drift, because they count by accumulating small ticks, and browsers deliberately slow those ticks down in background tabs to save battery. This one is different: the moment you press start it records the exact wall-clock time the countdown should end, and every frame it simply measures how long is left until that fixed end time. If you switch tabs, lock your phone, or the tab is throttled, the remaining time is recomputed from the real clock the instant you come back, so a 30-minute timer is still a 30 minutes timer rather than however long the throttled ticks happened to add up to. On phones the page asks for a screen wake lock while the countdown is running, where the browser allows it, so the display does not sleep mid-count. The alarm is synthesised in the browser with the Web Audio API, which means there is no audio file to download and the chime is ready the moment you start.

Other timer lengths

Need a different length? These are the timers people most often reach for alongside a 30-minute timer:

• 20 minutes timer
• 25 minutes timer
• 45 minutes timer

Frequently asked questions

Why are so many meetings 30 minutes?

Thirty minutes is the default calendar slot because it is long enough to cover a focused agenda and short enough to keep people engaged and to fit several into a day. Treating the limit as real, with a visible timer, keeps the discussion tight.

Is 30 minutes the Pomodoro long break?

It is at the top of the recommended range. After four 25-minute Pomodoros you take a longer break of 15 to 30 minutes to recover before the next set. Thirty minutes is the fuller version of that rest.

Does the timer keep counting in the background?

Yes. The countdown is fixed to an end time when you start, so it stays accurate even if you switch tabs or your screen dims, and the alarm sounds when the half hour is up.

Does the 30-minute timer work offline?

Yes. Once the page has loaded, the countdown runs entirely in your browser using your device clock, so it keeps working with no connection. The alarm is generated in the browser too, so there is no sound file to download.