Online Timer

How to set a timer

1. Stay on the Timer tab, which is open when the page loads.
2. Type hours, minutes and seconds, or tap a preset such as 5 minutes. Add a name like “Math quiz” if you want one.
3. Press Test sound once, so you know the alarm is loud enough.
4. Press Start. You can pause, resume or reset at any time.
5. At zero, the alarm plays and the timer keeps counting up as overtime until you press Stop alarm.

Need something other than a countdown? The stopwatch, Pomodoro, interval and clock tabs work the same way, and a running timer keeps going while you switch between them.

Popular timer lengths

Most people reach for a round number on any online timer. Need a 15 minute timer for a reading block, or a 1 hour timer for exam practice? Tap the matching preset and press Start.

Preset timer lengths and what people use them for

Length	What people use it for
10 seconds	A quick hold in a stretch, or a breathing break
30 seconds	A short stretch between sets
1 minute	A plank, or brushing teeth
2 minutes	A warm-up drill or a quick reading sprint
3 minutes	A boxing round, or steeping tea
5 minutes	A quick quiz, or brewing tea
10 minutes	A classroom warm-up
15 minutes	A reading block or a quick cleanup
20 minutes	A power nap or a homework sprint
25 minutes	One Pomodoro focus session
30 minutes	A workout circuit
45 minutes	A class period or a long study block
60 minutes (1 hour)	Exam practice
2 hours	A full practice test, or a long project session

Stopwatch with laps

A stopwatch counts up from zero, so it tells you how long something took. This free online stopwatch shows hours, minutes, seconds and hundredths of a second. Runners, swim coaches and science lab partners use the lap button to record split times without stopping the clock.

Each lap time is the difference between two totals. Here’s an example. You press Lap at a total of 30.00 seconds, then again at 1:15.00.

Worked lap example

Lap	Lap time	Total time
1	30.00	30.00
2	45.00	1:15.00

Lap 2 is 1:15.00 minus 30.00, which is 45.00. When you’re done, use “Download laps (CSV)” to open the times in a spreadsheet, or “Copy laps” to paste them into a message. If you refresh the page by accident, a running stopwatch picks up where it was in that same browser tab.

Pomodoro and study timer

The Pomodoro Technique cuts work into short, focused blocks. A Pomodoro set is four 25-minute focus sessions, with a 5-minute break after each one and a longer 15-minute break after the fourth.

Pomodoro structure

Phase	Default length	When
Focus	25 minutes	Four times per set
Short break	5 minutes	After focus sessions 1, 2 and 3
Long break	15 minutes	After focus session 4

Students like this study timer because 25 minutes feels small enough to start. You say, “I’ll just do one block of homework,” and the timer does the rest. Dots under the digits show how far you are through the set of four.

The break matters as much as the focus block. Stand up, drink water, look out a window. Scrolling your phone doesn’t rest your brain, and skipping breaks only makes the next block harder.

All three lengths are editable. At each phase change you’ll hear the sound once. The next phase waits for you unless you turn on “Auto-start next session,” which is off by default.

Interval and Tabata timers for workouts

An interval timer alternates work and rest for a set number of rounds. You set the seconds of work, the seconds of rest and the rounds. The display shows the round, the phase (work in green, rest in amber) and the time left.

One Tabata round is 20 seconds of work and 10 seconds of rest, repeated 8 times, for a total of 3 minutes 50 seconds. There’s no rest after the last round, so the math is rounds × (work + rest) − rest, or 8 × (20 + 10) − 10 = 230 seconds. Another example: 30 seconds of work and 15 seconds of rest for 4 rounds is 4 × (30 + 15) − 15 = 165 seconds, or 2:45.

Interval presets

Preset	Work	Rest	Rounds	Total
Tabata	20 s	10 s	8	3:50
HIIT	30 s	15 s	10	7:15
Boxing	3 min	1 min	6	23:00
EMOM	60 s	0 s	10	10:00

With “Beep in the last 3 seconds of rest” turned on, you’ll hear three short beeps before the next round, so you can hear the change from across the gym. Turn on Keep screen on too, so your phone doesn’t lock between rounds.

A classroom and exam timer that behaves

Teachers need a classroom timer that does what it says. Open it on the projector, press Fullscreen, and the digits and ring fill the screen. Students in the back row can read it.

• Visual mode hides the numbers and shows only a shrinking ring. It’s a calm choice for young children and sensory-friendly rooms.
• Naming the timer (“Math quiz”) puts the task right on the screen.
• Overtime keeps counting after zero, with a minus sign, so an exam timer shows exactly how far over a student ran.
• Test sound lets you check the volume before class, so the alarm never surprises the room.

You can save a ready-to-go link too. For example, /online-timer/?cmode=timer&ctim=300&cname=Math%20quiz opens a 5-minute timer named “Math quiz”. Use “Copy link to this timer” to make your own. Links never start by themselves, because browsers block sound until you tap.

Digital clock and alarm

The Clock tab is a big digital clock with seconds, the day and the full date. It shows a 12-hour clock with AM/PM by default, and one tap switches to 24-hour time. Fullscreen turns an old tablet or second monitor into a wall clock.

This online clock also has one online alarm clock. Set a time, add a label if you like, and switch it on. When your local time matches, the sound plays on a loop until you stop it. Keep the tab open, because a web page alarm can’t ring after the tab is closed.

Need the time somewhere else? Check our world clock for cities around the globe.

How this timer stays accurate

When you press Start, the timer writes down the exact moment it should finish. Many times a second, it looks at the clock and subtracts. It never counts seconds one by one.

That matters because a busy page or a slow phone can skip beats. A timer that adds up seconds slowly drifts. This one can’t drift, because the finish time is fixed and the display is always worked out from the real clock.

Background tabs help show the difference. Browsers slow down pages you aren’t looking at. When you come back, the display fixes itself instantly. If time ran out while you were away, the alarm sounds and the overtime appears right then.

One honest limit: a locked phone may delay the sound, even though the time is still right. For important timers, use Keep screen on.

Timer vs stopwatch vs clock

Differences between a timer, a stopwatch and a clock

Tool	What it does	Example
Timer	Counts down to zero, then signals	A 10-minute quiz
Stopwatch	Counts up and measures	Timing a 400-meter lap
Clock	Shows the time of day	Checking if it’s 3:45 PM

Tips for finishing on time

• Put it where you can see it. An online timer in a hidden tab is easy to ignore. Use Fullscreen or a second screen.
• Name it. “Draft intro” is a clearer job than “25 minutes.”
• Use overtime honestly. If you hit −05:00, that’s useful information for planning the next block.
• One timer, one job. Start a fresh timer for each task so you can see how long things really take.
• Test the sound first. It takes two seconds and saves a missed alarm.

Frequently asked questions

Last updated: November 2026

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