Medium timers (10–45 minutes)
Press start for a full-screen 30-minute timer that counts down 30:00 and rings a loud alarm when it reaches zero. You can pause and resume it, reset it, and the countdown keeps running accurately even if you switch tabs or your screen dims. No sign-up, nothing to install.
Ready · 30-minute timer
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 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.
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.
Need a different length? These are the timers people most often reach for alongside a 30-minute timer:
Browse the full set of countdown timers, or switch tools: the Pomodoro timer loops work and break intervals automatically, the online stopwatch counts up with laps, the alarm clock rings at a specific time of day, and the countdown maker counts down to a future date you can share or embed.