Online timer

How to use the online timer

Type the length into the hours, minutes and seconds boxes and press Start (or just press Enter). You don't have to do the arithmetic: 90 in the minutes box becomes 1 hour 30 minutes, and ↑/↓ step a box by one (hold Shift for ten). The quick-start row — 30 and 90 seconds, 1 to 60 minutes, and 2, 4 and 8 hours — starts a timer in one tap, which is the fastest way to set a 5 minute timer for a break or a 10 minute timer for a quiz.

Need to stop at a particular time rather than after a length? Pick a time in finish at a clock time (and optionally a date up to four days ahead) and the boxes fill with the time remaining. The finish time is worked out with real calendar dates, so the change between GMT and BST is handled correctly.

Each timer shows a progress ring, the time left and the clock time it will finish. Pause freezes it exactly, Resume carries on from the same millisecond, +1 min extends it without losing your place and Reset returns it to the length you set. Click the timer's name to relabel it at any point.

The keyboard works too: Space starts or pauses the selected timer (after you click Start or a preset, focus moves to the new timer, so the next Space pauses it rather than starting a second one), R resets it, + adds a minute, F goes full screen, N adds a new timer and Esc silences a ringing alarm.

Running several timers at once

Cooking a roast with three sides, running stations in a classroom or juggling laundry and a video call? Press Add timer to put another card beside the first — up to twelve at once, each with its own label, length, alarm state and full-screen button. If the selected timer is already running, pressing Start or a preset automatically creates a new timer rather than overwriting the one in progress.

The browser tab always shows the timer that will end next, for example “3:12 Pasta (+2)”, where the number in brackets is how many other timers are running. When one finishes the title flashes Time's up! with its label, so you can spot it among a row of tabs.

Each card has an At zero menu. Ring is a normal timer. Ring and repeat plays one short alarm and immediately starts again, counting the rounds — ideal for interval training or a reminder every 20 minutes. Ring and start next timer chains the card to the next one along, so you can build a sequence such as 25 minutes work, 5 minutes break, 10 minutes review. If the page only notices the end late (a throttled background tab), the overshoot is carried into the next round, so a sequence never slips.

If you need to measure how long something takes rather than count down, use the online stopwatch; for focused work blocks, the Pomodoro timer alternates work and breaks for you.

Why it stays accurate in a background tab and after sleep

Many online timers count down by adding one second every time the browser runs a repeating timer. That drifts: browsers deliberately slow timers in hidden tabs to save battery — Chrome can delay them to once a minute after a tab has been hidden for five minutes. This timer never counts ticks. It records the moment you pressed Start and works out the time left whenever it redraws.

It records that moment on two clocks. The high-resolution clock gives smooth, millisecond-accurate display, but on macOS, iOS and Linux it stops while the device sleeps. The ordinary wall clock keeps going. Whenever the wall clock has moved on more than a second beyond the high-resolution one — which only happens after sleep or a screen lock — the timer trusts the wall clock. So a 30 minute timer that was running when you closed the lid for ten minutes shows about 20 minutes left when you open it, and ends at its original finish time.

The alarm is handled separately. When you start a timer, the finish sound is booked in advance on the Web Audio clock, which runs on the audio thread and is not throttled with the page, so it sounds on time in a background tab. The audio clock also stops during sleep, so when the page wakes it checks and re-books the alarm; if the timer finished while the machine was asleep, it rings straight away. A notification (if you turned Notify me on) and the flashing tab title follow as soon as the browser runs the page.

Two honest limits: while the computer is asleep, the phone is locked or the browser is closed, nothing on a web page can make a sound — you get the alarm when you come back. And phones, particularly iPhones, suspend audio in background tabs, so keep the page on screen with Keep screen on ticked for anything important.

Alarm sounds, notifications and sharing

Choose between three alarms, all synthesised in your browser so nothing is downloaded: Soft chime (a descending three-note bell, good for offices and classrooms), Digital beeps (the classic kitchen-timer pattern, cuts through background noise) and Alarm bell (a rapid ringing bell for when you might be in another room). Press Test to hear one and set the volume slider. The Ring menu sets how long it goes on: once, 10 seconds, 1 minute, 5 minutes or until you stop it (up to 30 minutes). Repeating and chained timers always play one short alarm so they don't talk over the next round.

Tick Notify me to get a system notification when a timer ends; the browser asks for permission once, and only then. If you previously blocked notifications, allow them again from the padlock or site settings icon next to the address bar. Keep screen on uses the Screen Wake Lock API to stop your phone or laptop dimming while a timer runs.

The copy-link button on each timer produces an address such as /online-timer/?t=10m&label=Tea. Anyone who opens it gets the same timer, ready to start. The t value accepts 90s, 25m, 1h30m, 1:30:00 or a plain number of minutes, and ?until=17:30 opens a timer that finishes at that time. Adding &start=1 starts it immediately — handy for a bookmark or a link on a classroom whiteboard. Boiling eggs? The dedicated egg timer works out the time for you.

Frequently asked questions