What is Stopwatch & Countdown Timer?
A stopwatch measures how much time has passed, while a countdown timer measures how much time is left. This page gives you both in one place. Use the stopwatch to time a run, a presentation, a chemistry experiment or a round of a game, and record laps along the way. Use the countdown timer for cooking, study sessions, workouts, meetings or the classic twenty-five minute focus block. It opens instantly in any browser, needs no installation and keeps working while you switch between tabs, so it is ready whenever you need a quick, reliable clock.
How Does It Work?
The stopwatch reads your device clock when you press Start and again each time the display updates, so the time stays accurate even if the browser is busy. Lap times are the difference between two readings. The countdown works from a fixed end time rather than counting ticks, which means it stays correct even when a background tab is slowed down by the browser. When it reaches zero, the page plays a short tone generated by your browser's own audio engine. All of this runs locally. Nothing is uploaded, recorded or sent to a server.
How to Use It
- Choose the Stopwatch or Countdown timer tab at the top of the tool.
- For the stopwatch, press Start, press Lap to record split times, and press Pause or Reset when you finish.
- For the countdown, tap a preset such as 25 min, or type your own hours, minutes and seconds.
- Press Start. The large display and the progress bar show the time remaining.
- When the alarm sounds, press Stop alarm, or press Start again to repeat the same countdown.
Key Features
- Stopwatch accurate to a hundredth of a second
- Unlimited laps with split and total times, plus fastest and slowest highlights
- Countdown with 5, 10, 25 and 45 minute presets and custom hours, minutes and seconds
- Audible alarm with an on and off switch and a test button
- Both tools keep running when you change tabs inside the page
- Works on phones, tablets and computers, and nothing is sent to a server
Frequently Asked Questions
Will the timer still ring if I switch to another browser tab?
Usually yes. The countdown measures time against the clock, so it finishes on time even when the tab is in the background. The browser tab title also shows the remaining time, and some browsers may delay the sound by a second.
Why did I not hear the alarm?
Check that Alarm sound is switched on and your device volume is up. Browsers only allow sound after you have interacted with the page, so press Start yourself and use the Test sound button to confirm that it works.
How do I set a timer longer than one hour?
Type the hours into the Hours box, for example 2 hours and 30 minutes. The display then switches to an hours, minutes and seconds format, and you can go up to 99 hours.
What do Fastest and Slowest mean in the lap list?
Once you have recorded two or more laps, the shortest lap is tagged Fastest and the longest is tagged Slowest. They are based on each lap's own duration, not on the running total.
Does the stopwatch keep my time if I refresh the page?
No. Nothing is saved or uploaded, so refreshing or closing the page clears the stopwatch, the laps and the countdown. Use Copy laps before you leave if you want to keep your times.