Focus & study timers
Press start for a full-screen 45-minute timer that counts down 45:00 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 · 45-minute timer
Forty-five minutes is the length of a school class period, a university lecture, a typical therapy session, and a popular extended-focus work block. It maps neatly onto the natural rhythm of adult attention, which tends to wane somewhere between forty-five and ninety minutes of sustained concentration, making it a sustainable interval for genuinely deep work.
The forty-five-minute block sits inside a well-documented pattern in how attention works. Concentration is not a flat resource you can spend evenly across a day; it rises, peaks, and decays in cycles, and for most adults a single uninterrupted stretch of high-quality focus lasts somewhere between forty-five and ninety minutes before returning diminishes. Schools and universities settled on forty-five-to-fifty-minute periods through a century of trial and error for exactly this reason — it is long enough to develop an idea but stops before the class glazes over. For your own work, a forty-five-minute timer is a good 'medium' setting: longer than a Pomodoro, so you can get into something complex that needs a running start, but bounded so that you take a real break before fatigue quietly turns the last fifteen minutes into low-value busywork. Follow it with a proper ten-to-fifteen-minute break, away from the screen, and the next block starts fresh rather than already depleted.
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 45-minute timer is still a 45 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 45-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.