Online Timer and Stopwatch
Set a countdown timer with an alarm, run a stopwatch with laps, or focus with a Pomodoro timer (25 minutes work, 5 minutes break) on one page. Press a preset from 1 to 60 minutes or type any time such as 5:00 or 1h30m. It keeps exact time in a background tab, and nothing to install.
Clock
| Lap | Split | Total |
|---|
Plan (115 min)
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Pomodoro plan: 4 blocks
| Step | Type | Length | Clock |
|---|---|---|---|
| 1 | Focus | 25 min | 00:00–25:00 |
| 2 | Short break | 5 min | 25:00–30:00 |
| 3 | Focus | 25 min | 30:00–55:00 |
| 4 | Short break | 5 min | 55:00–1:00:00 |
| 5 | Focus | 25 min | 1:00:00–1:25:00 |
| 6 | Short break | 5 min | 1:25:00–1:30:00 |
| 7 | Focus | 25 min | 1:30:00–1:55:00 |
Four Pomodoro blocks with short breaks take 115 minutes: 100 minutes of focus and 15 minutes of breaks. Run 8 blocks and a 20-minute long break comes after the 4th.
Example: cooking rice and a study session
Rice needs 12 minutes: type 12 min or 12:00, label it "Rice" and press Start. The tab title counts down, so you can keep browsing. For revision, choose Pomodoro, keep 4 blocks of 25 minutes and press Start: the timer moves to each break and back with a short alarm, and rings longer at the end of the last block.
How it keeps exact time
- End time, not ticks: pressing Start stores the exact finishing moment; the display shows the difference from the clock, so delays never add up.
- Background tabs: browsers slow down timers in hidden tabs; because the end time is fixed, the countdown is still right when you come back.
- Alarm: a separate check fires at the end time, beeps with the Web Audio API and vibrates phones that support it.
- Screen: while running, the page asks the browser to keep the screen on (Screen Wake Lock), and releases it on pause or reset.
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Popular uses
- Classroom and exams: full-screen countdown on a projector for quizzes and presentations.
- Exercise: stopwatch laps for running or plank holds; copy the laps into a spreadsheet.
- Cooking: rice, eggs or kuih steaming with a label so you remember what the alarm is for.
- Focus: Pomodoro blocks for study, work or typing practice with the Typing Test.
Sources
- Francesco Cirillo: The Pomodoro Technique and Wikipedia: Pomodoro Technique
- MDN: Screen Wake Lock API and MDN: why timers are delayed in background tabs
Note: Do not rely on a web page for safety-critical timing such as medication. Phones can suspend browsers when locked or on low battery; use a dedicated alarm for anything important.
Frequently asked questions
How do I set a timer for 5 minutes?
Press the 5 min preset, or type 5:00 (or 300, or 5 min) in the time box and press Start. When it reaches zero the alarm beeps 6 times and the phone vibrates. You can also open /online-timer/#t=5m to load a 5-minute timer straight away.
Does the timer keep running in another tab?
Yes. The time is worked out from the clock, not by counting ticks, so it stays exact when you switch tabs; the tab title shows the time left. While it runs the screen is kept awake where the browser allows it. If a phone locks and suspends the browser, the alarm sounds as soon as you return.
How do I record laps on the stopwatch?
Choose Stopwatch, press Start, then press Lap (or the L key) at each lap. Every lap shows its split and total time; the fastest is green and the slowest red. Copy laps gives you a CSV list for a spreadsheet.
What is the Pomodoro Technique?
A time-management method created by Francesco Cirillo: work for 25 minutes, take a short break of about 5 minutes, and after 4 work blocks take a longer break of 20 to 30 minutes (20 here by default). Four blocks with breaks take 115 minutes here. You can change the focus, short and long break lengths.
What are the keyboard shortcuts?
Space starts or pauses, L records a lap, R resets and F switches full screen. Shortcuts do not fire while you are typing in a box, so you can still type a time or label.
Why can't I hear the alarm?
Browsers only allow sound after you tap the page, so press Start rather than relying on a link alone. Check that Alarm sound is ticked, the volume is up, and on iPhone that the silent switch is off, because it can mute web page sound.
How long can the timer run?
The countdown accepts up to 100 hours, typed as 1:30:00, 1h30m or 90 min, and the stopwatch shows hours once it passes 60 minutes. Use +1 min to add time while a countdown is running.
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