Online Stopwatch & Countdown Timer

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What is a Stopwatch and Countdown Timer?

A stopwatch counts up from zero, so you can measure how long something takes. A countdown timer works the other way round: you set a time, and it counts down to zero and then lets you know. Put together, they cover most everyday timing jobs, from timing a run or a speech to reminding you when the food is ready or when a break is over.

This tool has both on one page. Switch between the Stopwatch and Countdown tabs as you need, and keep the page open in a tab while you work.

How to Use the Stopwatch

1. Open the Stopwatch tab.
2. Click Start. The display counts up in hours, minutes, seconds and fractions of a second.
3. Click Lap each time you want to record a split time. Each lap is added to the list below the display.
4. Click Pause to stop the clock for a moment, and click Start again to continue from where it stopped.
5. Click Reset to set the stopwatch back to zero and clear the lap list.

How to Use the Countdown Timer

1. Open the Countdown tab.
2. Enter the hours, minutes and seconds you want, or tap one of the presets: 1 min, 5 min, 10 min or 30 min.
3. Click Start. The timer counts down toward 00:00.
4. When it reaches 00:00, a beep plays.

Make sure that your device volume is on. Browsers usually allow sound only after you have clicked or tapped on the page, which is why the timer starts with a click.

What You See on the Page

Item	Meaning
Stopwatch and Countdown tabs	Switch between counting up and counting down
Large display	The time in hours, minutes, seconds and, on the stopwatch, fractions of a second
Start, Pause, Reset	Start the clock, stop it for a moment, or set it back to the beginning
Lap button and lap list	Records a split time and shows all recorded laps below the stopwatch
Hours, minutes, seconds inputs	Where you set the countdown time
Presets (1, 5, 10, 30 min)	One-tap countdown times
Beep	Plays when the countdown reaches 00:00
Browser tab title	Shows the time and the mode, for example 05:00 - Countdown
Fullscreen button	Shows the timer in a larger display

Lap Time vs Total Time

When you record a lap, there are two useful numbers. Lap time is how long that lap took. Total time, also called split time, is how much time has passed since the start.

Lap	Pressed Lap at (total time)	Lap time
1	00:30	00:30
2	01:05	00:35 (1:05 minus 0:30)
3	01:40	00:35 (1:40 minus 1:05)

The stopwatch keeps running while you record laps, so you do not lose any time. Lap times are handy for runners, swimmers, people who time each step of a task, and anyone who wants to see whether they are speeding up or slowing down.

Countdown Presets

Preset	Handy for
1 min	Quick tasks, short drills, a one-minute pitch or rest
5 min	Short breaks, a quick talk, a brief warm-up
10 min	A short study block, a brief meeting item, a cool-down
30 min	A longer study block, a meeting slot, a longer task

For any other time, type the hours, minutes and seconds yourself.

Time Conversion Cheat Sheet

Seconds	Minutes and seconds	Hours, minutes and seconds
60	1:00	00:01:00
90	1:30	00:01:30
300	5:00	00:05:00
600	10:00	00:10:00
1,800	30:00	00:30:00
3,600	60:00	01:00:00
5,400	90:00	01:30:00

To turn minutes into seconds, multiply by 60. To turn seconds into minutes, divide by 60.

What Can You Use It For?

Use	Tool
Timing a run, a swim or a workout, and recording laps	Stopwatch with Lap
Resting between sets or exercises	Countdown with a preset or a custom time
Practising a speech or a presentation	Stopwatch, or a countdown for the time you are given
Study blocks and timed practice papers	Countdown
Cooking, baking and reminders at home	Countdown. Follow the time given in your recipe or on the packet
Games, quizzes and classroom activities	Countdown for the round, stopwatch for how long a turn took
Timing a task to see how long it really takes	Stopwatch
Meetings and workshops	Countdown for each agenda item

If you want to work in focused sessions with scheduled breaks, the Pomodoro Timer is built for that.

Time in Your Browser Tab

The tab title changes with the timer, for example 05:00 - Countdown. This lets you work in another tab or window and still see how much time is left, without going back to the timer page. Keep the timer page open in its own tab, and do not close it until you are done.

Fullscreen Mode

• Click the Fullscreen button to fill the screen with the timer, which makes the digits much easier to read from a distance, for example at a gym, in a classroom or on a shared screen.
• To leave fullscreen, press Esc or click the button again.
• Not every phone or browser allows it. Some do not let web pages go fullscreen, so the button may not work on your device. You can still make the page bigger by rotating your phone sideways.

Accuracy and Background Tabs

• Good for everyday use. The stopwatch is fine for workouts, cooking, talks, games and similar jobs.
• The display is more precise than your finger. The tool shows fractions of a second, but your reaction time when you press a button is much larger, so do not read too much into the last digit.
• Not for official timing. Do not use it for official sports results, laboratory measurements, safety-related timing or anything where exact timing is required.
• Background tabs are slowed down by browsers. To save power, browsers slow down pages that you are not looking at. The time is worked out from the clock, so it stays correct, but the display may update less often and the alarm can come a little late.
• Phones can pause pages completely. When the screen is locked, the page may stop, and the alarm may be late or may not play. Keep the screen on, or use your phone's own clock app for anything important.

About the Alarm

• A beep plays when the countdown reaches 00:00.
• Your device volume must be on and not muted. On some phones, silent mode also silences web page sound.
• Browsers allow sound only after you have interacted with the page, so start the timer with a click or tap.
• Headphones or a Bluetooth speaker can change where the sound comes out. Check before you rely on the alarm.

Tips

• Keep the timer page in its own tab and watch the time in the tab title while you work.
• Check the volume before you start a countdown. A test with the 1 min preset takes one minute.
• Use Lap for every repeat. Laps make it easy to compare your first and last round.
• Write down important lap times. They are not saved when you leave the page.
• Use fullscreen for group activities, so that everyone can see the time.
• On a phone, keep the screen on, and plug in the charger for long timers.
• Use a second reminder for important things. Use your phone's clock or alarm app as well for a flight, a medicine or an appointment.

Common Mistakes

• Closing or reloading the page: The timer stops, and the running time and laps are gone.
• Forgetting that sound needs a click: Start the timer yourself after you open the page.
• Muted device: The countdown ends silently if the volume is off.
• Relying on a locked phone: The page may be paused when the screen is off.
• Mixing up lap time and total time: Lap time is the time since the last lap, and total time is the time since the start.
• Mixing up minutes and seconds in the inputs: Check the hours, minutes and seconds boxes before you press Start.
• Using it for official timing: Use certified equipment when exact timing matters.

Privacy

• The stopwatch and the timer run in your browser, and nothing you do on this page is sent to our server.
• We do not save your times or laps.
• No signup, no account and no app install are needed.

Frequently Asked Questions

How do I use the online stopwatch?

Open the Stopwatch tab and click Start. The time counts up in hours, minutes, seconds and fractions of a second. Click Lap to record a lap, Pause to stop for a moment and Start again to continue, and Reset to go back to zero.

What is the difference between lap time and total time?

Lap time is the time since the previous lap, or since the start for the first lap. Total time, also called split time, is the time from the start to the moment you pressed Lap. For example, if you press Lap at 30, 65 and 100 seconds, the total times are 30, 65 and 100 seconds and the lap times are 30, 35 and 35 seconds.

How do I set the countdown timer?

Open the Countdown tab, enter the hours, minutes and seconds, or tap a preset of 1, 5, 10 or 30 minutes, then click Start. The timer counts down to 00:00, and a beep plays when it gets there.

Will I hear the alarm when the countdown ends?

A beep plays when the countdown reaches 00:00. Make sure your device volume is on and not muted. Browsers usually allow sound only after you have clicked or tapped on the page, which is why you start the timer with a click or tap.

Does the timer keep running if I switch to another tab?

Yes, keep the page open and switch freely to other tabs. The time is worked out from the clock, so it stays correct, and the tab title keeps showing the time. Browsers slow down pages in the background, so the display may update less often and the alarm can come a little late. Do not close the tab or the browser, because the timer stops when the page is closed.

Will the timer and alarm work if my phone screen is locked?

Not always. Phones and browsers can pause web pages when the screen is locked or the browser is in the background, so the alarm may be late or may not play. For best results on a phone, keep the screen on and the page open. For something important, such as a medicine reminder or a flight, use your phone's own clock app as well.

How accurate is the stopwatch?

It is good for everyday timing, such as workouts, cooking, presentations and games. The display shows fractions of a second, but the real accuracy depends on your device and browser, and on how quickly you press the buttons. It is not meant for official sports timing, laboratory work or anything where exact timing matters.

Why does the browser tab show the time?

The tab title changes with the timer, for example 05:00 - Countdown, so you can see the remaining time while you work in another tab or window.

How do I use fullscreen mode?

Click the Fullscreen button to show the timer in a larger display, which is useful in a gym, a classroom or from across a room. Press Esc or use the button again to leave fullscreen. Some phones and browsers do not allow web pages to go fullscreen, so the button may not work everywhere.

What happens if I reload or close the page?

The timer stops, and the running time and the lap list are not kept. Copy or write down your lap times before you leave the page.

What is the difference between this and the Pomodoro Timer?

This tool is a general stopwatch and countdown timer. The Pomodoro Timer is built for the Pomodoro study and work method, with focus, short break and long break modes. Use this tool when you simply need to time something.

Is my data sent to a server?

No. The stopwatch and the timer run in your browser using JavaScript, and nothing you do on this page is sent to our server.

Is this stopwatch and timer free, and does it work on mobile?

Yes. The tool is free and needs no signup or app install. It is designed for phone screens as well as desktop.