Секундомір і таймер

A stopwatch and countdown timer in one

This free online stopwatch and timer covers both jobs in a single page. The stopwatch counts up with lap and split times for timing workouts, tasks, experiments and games; the countdown timer counts down from any duration with a clear alarm for cooking, studying, workouts and presentations. Switch between them with one tap and the large, monospaced readout stays easy to read across the room.

There's nothing to install and no account to create — it runs entirely in your browser, so it's instant, private and works offline once loaded.

Stopwatch with lap and split times

Press Start to begin, Lap to capture a split without stopping the clock, and Reset to clear. Every lap is logged with both its split time (since the previous lap) and the total elapsed time, and the tool highlights your fastest and slowest laps automatically so patterns jump out — handy for running intervals, swimming sets or comparing attempts. The readout is precise to a hundredth of a second, and you can copy the full lap list to paste into a note or spreadsheet.

Countdown timer with alarm and presets

Set hours, minutes and seconds, or tap a preset — 1, 3, 5, 10, 15 or 25 minutes — and press Start. When the countdown hits zero it plays a repeating alarm sound, flashes the display, and can show a browser notification so you're alerted even if the tab is in the background. Turn on Repeat to loop the same duration automatically — perfect for interval training or batch cooking — or switch Sound off for a silent, visual-only timer.

Full-screen mode and a big, readable display

Tap Full screen and the time fills your whole display in giant digits, with the controls still within reach. It's built for shared spaces — a classroom timer the back row can read, a gym clock, a quiz countdown, or a talk where the speaker needs to see the time at a glance. Press Esc to drop back to the normal view at any time.

Accurate even in a background tab

Many web timers drift because they count animation frames, which browsers slow down for hidden tabs. This one is timestamp-based: it works out elapsed and remaining time from the system clock on every update, so the numbers stay correct no matter how long you've been on another tab, and a backup alarm is scheduled so the timer still rings on time. While timing, it also asks to keep your screen awake so the display doesn't dim mid-session on supported devices.

How it compares to other online timers

Google's built-in timer (the widget that appears when you search "set timer") is fast for a single countdown but it vanishes the moment you leave the search page, has no lap support, no full-screen mode, and stops tracking if you close the tab. Timeanddate.com's stopwatch is solid but buries the feature behind navigation and loads ad-heavy pages. Online-stopwatch.com is widely used but serves heavy banner ads and doesn't work offline.

UtiloKit's stopwatch and timer has no ads, runs entirely client-side so it works offline, records unlimited lap splits, shows a proper full-screen display, and sends browser notifications when the countdown ends — all without requiring any sign-up or account.

Stopwatch vs timer — which do you need?

If you want to know how long something takes, use the stopwatch (it counts up from zero). If you want to be told when a set amount of time is up, use the timer (it counts down to zero and alarms). A race, a phone call or a workout suits the stopwatch; an exam, a recipe or a focus session suits the timer. For structured study blocks with automatic breaks, our companion Pomodoro timer builds on the same countdown idea.

Private, free and works offline

There's no sign-up, no cost and no tracking. The stopwatch and timer run 100% locally in your browser, so nothing you time is ever uploaded — and because it's all client-side, it keeps working without a connection. Bookmark it as your go-to online stopwatch and countdown timer for sport, study, cooking and the classroom.

A brief history of timekeeping

Measuring elapsed time accurately has driven some of the most important inventions in history. The first mechanical clocks appeared in Europe around 1300 and used an escapement mechanism — specifically the verge and foliot — to release energy from a falling weight one controlled tick at a time. This converted continuous motion into the discrete, countable beats that define a clock, though accuracy was limited to within fifteen minutes a day.

The next landmark was the marine chronometer. Longitude at sea can only be determined by comparing local solar time to the time at a known meridian — a calculation that demands a clock that keeps accurate time aboard a pitching ship. English clockmaker John Harrison solved this with his H4 pocket watch in 1761, accurate to within five seconds over a 47-day voyage to Jamaica. Harrison's work enabled precise navigation and, indirectly, the expansion of global trade and exploration.

The modern era of timekeeping began in 1927 when Warren Marrison built the first quartz crystal oscillator clock. A quartz crystal vibrates at exactly 32,768 Hz when an electric current is applied — a frequency precise enough to keep time to within a few seconds per month. Quartz is the technology behind every digital watch and stopwatch sold since the 1970s. Even further precision arrived with the atomic clock: since 1967 the SI second has been defined as 9,192,631,770 oscillations of a cesium-133 atom, giving accuracy to within one second every 300 million years — the reference standard that ultimately underpins the browser clock your stopwatch runs on.

How digital stopwatches actually work

A digital stopwatch is fundamentally a counter driven by a crystal oscillator. The oscillator emits pulses at a fixed frequency — the counter increments with each pulse, and the display divides the accumulated count by the oscillator frequency to produce an elapsed time. Because the oscillator frequency is extremely stable, the measurement is far more accurate than any mechanical alternative. The key distinction between a clock and a stopwatch is intent: a clock tracks current time relative to an external reference (sunrise, UTC), while a stopwatch measures the duration between a start event and a stop event with no reference to the outside world.

Lap times and split times are often used interchangeably but mean different things in precision timing. A lap time (or split time in some conventions) is the time elapsed since the previous lap marker — it tells you how fast that individual segment was. A cumulative split is the total elapsed time from the very start, which lets you reconstruct the entire run. Both numbers are useful: laps reveal pace variation, cumulative splits show overall progress.

Older mechanical stopwatches used a flyback mechanism — pressing the crown once stopped the hands, a second press snapped them back to zero and immediately restarted. More complex rattrapante (double chronograph) stopwatches had two coaxial second hands: pressing a side button released a second hand to freeze at the lap time while the first hand kept running, then pressing again snapped the frozen hand to rejoin the running hand. These mechanical ingenuities are now replicated in software with a single button.

Timekeeping in athletics and motorsport

Professional sport demands timing far beyond what a hand on a button can deliver. World Athletics (formerly IAAF) requires all track events to be timed to 1/100 of a second, with photofinish cameras used for official results at distances where margins are close. A photofinish camera is not a conventional snapshot camera — it is a high-speed line-scan camera positioned precisely at the finish line, capturing a single vertical slice of the line at over 1,000 frames per second and assembling those slices into a composite image. The camera records every athlete at the exact instant their torso crosses the line, allowing times to be read to 1/1000 of a second from the image.

Usain Bolt's 100 m world record of 9.58 seconds, set in Berlin in 2009, illustrates how tight the margins are: his average speed was 10.44 m/s, meaning a timing error of even 10 milliseconds would shift a result by about 10 cm — enough to change a medal. Human reaction time plays a role too: the average sprinter takes roughly 150 ms to respond to the starter's gun. World Athletics defines a false start as a reaction faster than 100 ms (later revised to rely on measured force-plate data rather than a fixed threshold), reflecting the consensus that a sub-100 ms reaction is a movement that began before the gun was consciously perceived.

In Formula 1, timing is even more granular. Each car carries a GPS transponder that reports position to within about one millimetre, and timing loops buried in the track surface record sector and lap times to the millisecond. These split-second sector times are how engineers evaluate whether a setup change has actually improved the car in a specific part of the circuit — a 15-millisecond gain in Sector 2 that costs 20 milliseconds in Sector 3 is a net loss, and the granularity of the data makes that immediately visible.

The Pomodoro Technique and time-boxing for focus

In 1987, Francesco Cirillo was a university student struggling to concentrate. Using a tomato-shaped kitchen timer (pomodoro is Italian for tomato), he developed a method now known as the Pomodoro Technique: work in a focused 25-minute block, take a 5-minute break, and after four consecutive blocks take a longer 25–30 minute break. The technique is backed by attention-span research showing that focused attention deteriorates after roughly 20–30 minutes of sustained cognitive effort without rest — short breaks restore performance rather than interrupt it.

Time-boxing — assigning a fixed maximum duration to a task rather than working until it is finished — is a broader productivity principle that encompasses the Pomodoro method. Agile software development uses the same concept with sprints: a two-week time box in which a team commits to a defined body of work. The constraint forces prioritisation and creates a natural review cadence. For individual work, time-boxing a task to 30 minutes prevents Parkinson's Law (work expands to fill available time) and makes it easier to get started because the commitment feels bounded.

The choice between a countdown timer and a stopwatch for focus work is not trivial. A countdown timer creates urgency and commitment — you set 25 minutes and work against a deadline, which many people find motivating and easier to respect as a boundary. A stopwatch measures actual time spent, which is useful for tracking how long tasks really take across a week. Both approaches are valid; the countdown suits structured Pomodoro cycles while the stopwatch suits open-ended deep work sessions where you want an honest record rather than a pressure mechanism.