Online Stopwatch & Countdown Timer
A precise stopwatch with laps and a countdown timer with an alarm. Both keep correct time even when this tab is in the background.
How to use the stopwatch and timer
- Stopwatch: press Start, use Lap to record split times, Pause to stop and Reset to clear everything.
- Timer: open the Countdown timer tab, enter hours, minutes and seconds (or tap a preset) and press Start.
- When the timer reaches zero you hear an alarm. Press Stop alarm to silence it. You can switch to another tab while it runs.
Features
Laps with best and worst
Every lap shows its own time and the running total, with the fastest and slowest marked.
Accurate in the background
Time is measured from the clock, so it stays correct when the tab is hidden.
Sound alert
A clear beep at zero, with a test button so you can check your volume first.
Private
Everything runs in your browser; nothing is sent anywhere.
A simple stopwatch and timer that stays accurate
This page combines two everyday tools. The stopwatch counts up in hundredths of a second and records laps, which is handy for workouts, running, cooking, presentations or timing how long a task really takes. The countdown timer counts down from any time up to 99 hours and plays an alarm when it reaches zero, so you can use it for study sessions, the Pomodoro technique, tea, baking, games or a quick break.
Browsers slow down ordinary timers in tabs you are not looking at, which can make simple web timers run late. Toolzuki avoids this by never counting ticks. It stores the start or end time and works out the difference from your device clock every time it updates, using a background worker that is not throttled. The result: if you switch tabs for ten minutes, the display is still correct when you come back, and the alarm sounds on time.
For the sound to play, your device volume must be on and the browser must allow audio, which it does after you press Start. The page title also shows the time left, so you can see it on the tab. Nothing is uploaded or saved; close the tab and everything is gone.
Frequently asked questions
Does the timer work when the tab is in the background?
Yes. The timer uses your device clock and a background worker instead of counting ticks, so it stays accurate when you switch tabs. The time left also appears in the browser tab title.
Why can I not hear the alarm?
Check that your device is not muted and that the "Play a sound" box is ticked. Use the Test sound button to check the volume. Some phones block sound when the screen is locked, so keep the screen on for important timers.
How accurate is the stopwatch?
It shows hundredths of a second and is based on your device clock. It is accurate enough for sport, cooking and study, although it cannot beat dedicated hardware for official timing.
How many laps can I record?
As many as you like. The fastest lap is marked in green and the slowest in red once you have at least two laps.
Is anything saved?
No. Times and laps stay in the page only and are cleared when you close or reload it.