Medium timers (10–45 minutes)
Press start for a full-screen 15-minute timer that counts down 15:00 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 · 15-minute timer
Fifteen minutes — a quarter of an hour — is the smallest block most calendars schedule, and a genuinely useful chunk of focused time. It is the canonical 'power nap' length, a standard short-cleaning sprint, and long enough for a small but complete piece of deep work. Many people find a quarter hour easier to commit to than a full half-hour, which makes it a great unit for chipping away at big tasks.
Sleep scientists generally recommend keeping a daytime nap to between 10 and 20 minutes, and fifteen sits right in the middle. The reason is the architecture of sleep. In the first fifteen-or-so minutes you stay in the lighter stages of non-REM sleep, from which you wake quickly and clear-headed. Push much past twenty minutes and you start to descend into deep slow-wave sleep, and being jolted out of that stage produces 'sleep inertia' — the heavy, groggy, worse-than-before feeling that makes long naps backfire. A fifteen-minute timer lets you get the restorative benefit of a short nap, the alertness boost and the memory consolidation, while waking before your brain commits to the deep sleep you would struggle to surface from.
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 15-minute timer is still a 15 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 15-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.