Why it keeps time in a background tab
Browsers slow down or pause scripts in tabs you are not looking at, to save battery. A timer that adds one second every time its code runs therefore falls behind. This one stores the moment it should end, or the moment it started, and works out the time from the device clock whenever the screen is drawn, so the display is right the instant you come back. The end sound is scheduled in advance on the browser's audio clock, which keeps running in a background tab on desktop browsers. Phones may stop a page completely when the screen locks, so while a timer runs the page asks the browser to keep the screen on, where that is supported.
Sound and notification alerts
When a countdown or a focus phase ends you hear three short beeps, unless you untick the sound option. The page also shows a message and, if you allow it, a browser notification that appears even when another window is in front. The page only asks for permission when you press the notification button. If you blocked notifications earlier, allow them again in the site settings of your browser. Some phone browsers only show notifications from installed apps, so on a phone keep the page open and the sound on.
Stopwatch laps and the CSV file
Press Lap or L while the stopwatch runs to record a lap. Each row shows the lap time and the total time, newest first, and once there are three laps the fastest and slowest are marked. Download CSV saves every lap with its time in seconds and as a clock, ready to open in Excel or Google Sheets for training logs, presentations or timing tests. The display shows hundredths of a second, but the real accuracy depends on how quickly you tap.
The focus and break timer
Working in fixed blocks with short breaks helps many people study, revise or get through a long task. The default cycle is 25 minutes of focus, a 5-minute break, and a 15-minute break after every fourth session; change any of them, for example to 50 minutes of work and 10 of rest. With automatic start ticked, the next phase begins the moment one ends, timed from when the previous one was due, so the cycle never drifts. Skip moves straight to the next phase, and the counter shows how many focus sessions you have finished.
Keyboard shortcuts and saved timers
Space starts and pauses, R resets, L records a lap, and 1, 2 and 3 switch between the countdown, the stopwatch and the focus timer. The keys do nothing while you are typing in a box. Your timers are saved in this browser, so a reload or an accidental close does not lose them: a countdown that ended while the page was closed shows as finished, and a stopwatch carries on from when it started. Nothing is sent to us.