How to Use the Countdown Timer and Stopwatch
Select Countdown when you know how long an activity should last. Enter hours, minutes, and seconds or choose a preset, then start the timer. Select Stopwatch when you want to measure an open-ended activity and record laps or split intervals along the way.
Countdown
Useful for cooking, meetings, study blocks, presentations, breaks, and time-boxed work.
Stopwatch
Useful for workouts, practice drills, experiments, task timing, events, and repeated intervals.
Timing Accuracy in Active and Background Tabs
Browsers can slow ordinary intervals when a tab is hidden. The countdown avoids subtracting time one tick at a time: it stores the intended finish timestamp and recalculates what remains from the current clock. The stopwatch uses the browser's monotonic performance clock and derives the display from its start point. Both methods catch up after delayed screen updates.
Device sleep, battery-saving restrictions, or a suspended browser can still delay the moment a completion sound or notification appears. Use a dedicated safety alarm for medication, laboratory safety, critical cooking, or any situation where a missed alert could cause harm.
Stopwatch Laps and Split Times
Press Lap without stopping the stopwatch. Each row records the total elapsed time and the split since the previous lap. This makes it easy to compare repetitions while preserving the complete run. Copy the formatted summary or download CSV for a spreadsheet, training log, classroom activity, or project record.
Completion Sound and Browser Notifications
The completion chime is generated locally with the Web Audio API and does not require a downloaded sound file. Browsers commonly require a user action before sound can play, so starting the timer or selecting Test sound prepares the audio context. Optional notifications require permission from both the site and the operating system for the browser currently in use.
Private, Session-Based Timing
Timer labels, elapsed time, laps, copying, and CSV creation remain in the browser. There is no account and no upload step. The current session is intentionally cleared by a page refresh or closed tab, so export any lap records you want to keep.
Continue Your Productivity Workflow
Run structured focus-and-break cycles with the Pomodoro Timer, choose the next task or participant using the Random Picker & Wheel Spinner, calculate full shifts and unpaid breaks with the Work Hours & Timesheet Calculator, measure longer calendar intervals with the Duration Calculator, or organize an exam schedule with the Study Time Planner.