Countdown timer and stopwatch in one page
The countdown mode works for exams, cooking, workouts or focus sessions: set hours, minutes and seconds (or tap a preset), press Start, and the circle visually drains as time runs out. When it reaches zero a three-tone alarm plays and the browser tab title flips to "Time is up" — handy when the timer is in a background tab.
The stopwatch mode counts up with 10-millisecond precision and keeps a lap list: each lap records the split and total time. Switch between the two modes with the tabs on top; Space starts or pauses whichever mode is active.
Practical notes
- Timer accuracy depends on your device staying awake; screen-locked phones may pause JavaScript.
- The alarm is synthesized in the browser — make sure system volume is audible.
- Everything runs locally; no sign-in, no history on any server.
Frequently asked questions
Does the countdown stay accurate in a background tab?
Yes. The remaining time is recalculated from a timestamp rather than counted down tick by tick, so switching tabs or minimising the window does not slow it. The tab title shows the remaining time and flips to “Time is up” when it hits zero.
Will I hear the alarm if I am in another tab?
Yes, the page plays a three-tone alarm the moment the countdown reaches zero, and you can see the tab title change as well. Keep the tab open so the browser does not discard it, and check that neither the tab nor the system is muted.
How do I set a 20-minute timer quickly?
Type 20 into the minutes box, or click the 25-minute preset and adjust it. There are one-click presets for 1, 3, 5, 10, 15, 25 and 45 minutes, and Space starts or pauses whichever mode is active.
What is the difference between the countdown and the stopwatch?
The countdown runs down to zero and sounds an alarm, which suits exams, cooking and workouts. The stopwatch counts up with 10-millisecond precision and records laps, showing each lap split next to the running total.
Does the timer survive a page refresh?
No, reloading or closing the page clears both the countdown and the stopwatch. Set the time again after a refresh, and keep the tab open while timing anything long.
Can I use it as a Pomodoro or exam timer?
Yes: 25 minutes matches a Pomodoro work interval, 45 minutes suits a study block or an exam section, and the alarm sounds without any sign-in or install. Everything runs in your browser.