Live to the second
Second Clock and Second Timer
A clock that shows the seconds field, updating exactly on the boundary, plus a fast countdown for short intervals. Copy the reading, project it, or run a drill from it.
A second clock displays time down to the exact second rather than only hours and minutes. It's useful for timing tasks precisely, coordinating events, or tracking short intervals in real time. This page also includes a quick timer, so you can start a countdown in seconds with one click.
Live second clock
Hours
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Minutes
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Seconds
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Second timer
Count Down in Seconds
One click sets a common interval. Everything under two minutes is on the top row, because that is where a seconds timer earns its keep.
Space start or pause · R reset
Seconds
Minutes
Or type it
How to use it
Getting the Most Out of a Seconds Display
Coordinate an Exact Start
When two people need to begin at the same moment, agree on a clock reading rather than a countdown: "go at 10:15:30". Both watch the seconds field and start together, with no lag from a spoken count.
Measure Short Intervals
For anything from ten to ninety seconds, the timer is faster to set than a stopwatch is to read. Pick a preset, hit start, and the alert tells you when it is done.
Project It for a Room
Full screen makes the seconds readable from the back of a hall. Teachers use it constantly for short activities where "thirty seconds left" needs to be visible rather than announced.
In use
Where Seconds Actually Matter
Exams and Timed Practice
Practice papers only work if the timing is strict. Short presets let you run individual question drills, while the clock gives everyone the same visible start moment. For the whole paper, the longer timer with its 45 and 90 minute presets is the better fit.
Interval Training and HIIT
Twenty seconds on, ten seconds off. Forty-five and fifteen. These patterns live entirely in the seconds range, and being able to reset with one click between rounds is what makes them workable without a dedicated app.
Cooking Steps
Blanch for ninety seconds, rest for three minutes, whisk for thirty. The steps that go wrong in a recipe are usually the short ones, because they are the easiest to guess at and the least forgiving when the guess is off.
Speaking and Presenting
Rehearsing to a strict limit is the only reliable way to fit a talk into its slot. Run each section against a preset and you find out quickly which part needs cutting — usually the introduction.
Accuracy
Keeping the Seconds Honest
The clock is only as good as your device. Everything here reads the system clock. If your phone or computer has the wrong time, the seconds will be confidently wrong too.
Turn on automatic date and time, and automatic time zone, and leave them on. Devices that are set manually drift, sometimes by several seconds a week, and the drift is invisible until you compare two clocks side by side. Changing the time zone by hand while travelling is another common source of an hour-sized error that looks like a website bug.
If you need two screens to agree exactly — a start line and a finish line, say — nominate one device as the reference and have everyone read from it. Two independently correct clocks will still differ slightly, and no amount of syncing removes that entirely.
Step by step
How to Use the Second Clock & Timer
A clean live clock that updates every second, plus a fast timer with one-click presets. This clock updates precisely each second boundary for a smooth, accurate display — good for screenshots, presentations, and timing checks.
1) Use the Second Clock
The clock shows the current time down to seconds. It updates automatically once every second, so the display stays smooth and accurate. Use it when you need exact timing, for example “Start at 10:15:30”.
Press Copy time to copy the current time (HH:MM:SS), or Copy timestamp to copy a full date and time line for notes. Use full screen for presentations or classroom display.
2) Start the Timer
A fast countdown timer with an optional beep and browser notification when it ends. Use presets for instant setup, or enter your own hours, minutes, and seconds. Click any preset to set the timer automatically, then press Start to begin instantly.
Pause stops the countdown without resetting it, and Reset restores the timer to the values in the input boxes. Preview plays a test sound, which also unlocks audio in some browsers.
Preset buttons instantly set the timer to common durations like 30 seconds, 1 minute and 5 minutes. This is the quickest way to start timing tasks. Set the value without starting if you want to adjust the time before beginning, and use Enable alerts so notifications appear when the timer completes.
If your device time is incorrect, the clock and timer will also be incorrect. Keep automatic date and time enabled and avoid changing time zone manually unless necessary. When the timer finishes you'll hear a sound and get a browser notification, or an alert popup if notifications are blocked. If audio doesn't play, click Preview once to unlock sound in your browser.
In practice
Uses of a Second Clock & Online Timer
Seconds matter in many real-life situations. A second-level clock plus a quick timer helps you act with precision.
Exams and Timed Practice
Use the timer to simulate strict exam timing. Presets make it fast to run short drills (30 seconds, 1 minute, 5 minutes), while the second clock helps you coordinate “start now” moments across a whole room.
Interval Training
Intervals often depend on seconds: 20 seconds work and 10 seconds rest, 45 seconds and 15 seconds, and so on. The presets let you start instantly, and full screen makes it readable from a distance.
Cooking Steps
Cooking steps like “boil for 90 seconds” or “rest for 3 minutes” are easier with a one-click timer. Use alerts so you don't miss the finish while multitasking.
Public Speaking
Speakers often practise with strict time limits. Use 3, 5, 10, or 15 minute presets. The second clock also helps you start exactly on a scheduled second.
Classrooms
Teachers use seconds clocks for quick activities (“You have 30 seconds!”). Full screen mode is perfect for projecting in classrooms or meetings.
Focus Blocks
Use short timers for focus blocks: 10 minutes cleanup, 20 minutes writing, 30 minutes deep work, 5 minutes break. The progress bar helps you see how far you've gone at a glance.
Why Seconds Improve Time Management
- Start tasks exactly on schedule (“Begin at 02:15:00”).
- Measure small durations accurately (10–90 seconds).
- Improve pacing in exercise, speaking, and testing.
- Avoid missing deadlines by a few seconds.
Unlock Audio First
Many browsers require one click before playing audio. Press Preview once so the finish sound always works.
Enable Alerts for Background Use
If you switch tabs or minimise the browser, notifications help you catch the timer end instantly. If permission is denied, the page uses an alert popup fallback.
Use Full Screen on a TV
Full screen makes the numbers easy to see from far away. Great for workouts, classrooms, kitchens, and meetings.
Short intervals
Timing in Seconds
Anything under about two minutes is awkward to set on a general-purpose timer and trivial here.
The timer on this page is built for short intervals: a two second timer, a thirty second drill, a ninety second rest. The presets start at ten seconds so you are one click away from the common ones, and the clock above shows the seconds field live if what you actually need is a seconds counter rather than a countdown.
For counting things rather than time, use the online counter. For a countdown that targets a date rather than a duration, use the countdown timer.
Answers
Second Clock Questions
Precision, skipped digits, copying the reading and short-interval drills.
Will the timer keep running if I change tabs?
Yes. Modern browsers may reduce performance in background tabs, but the timer stays consistent because it is anchored to a finishing timestamp rather than counted tick by tick. Enabling notifications helps you catch the finish time even when you're doing other tasks.
Why is there no sound when the timer ends?
Your browser may block sound until you interact with the page. Click Preview once to unlock sound, then start the timer again. Also check the device volume and that the tab is not muted.
Can I use this on mobile?
Yes. The layout is responsive for desktop, tablet, and mobile. For best visibility, rotate your phone to landscape or use full screen.
What is a second clock?
A clock that shows the seconds field, not just hours and minutes. It sounds trivial, but it changes what you can do: you can agree to start something at 10:15:30 rather than "about quarter past", you can measure short intervals without a stopwatch, and you get a much stronger sense of time actually passing.
Why do the seconds sometimes appear to skip a number?
The display redraws on the second boundary, so if the tab was throttled or the machine was briefly busy, the redraw can land a fraction late and you see the next value instead. The underlying time is never wrong — it is read fresh from the system clock each time, not incremented.
How precise is the seconds display?
It shows whole seconds and it is aligned to the real second boundary rather than to whenever the page happened to load. If you need tenths or hundredths, use the stopwatch, which measures elapsed time rather than displaying clock time.
What does Copy timestamp give me?
A full date and time line suitable for pasting into notes, a log or a bug report — the kind of thing you want when recording exactly when something happened. Copy time gives you the shorter HH:MM:SS form for when you only need the clock reading.
Can I use short timers for interval training?
That is what the seconds presets are for. Common patterns are 20 seconds of work with 10 seconds of rest, or 45 with 15. Set the preset, go full screen so the figure is readable from across the room, and restart between rounds.
Why does my seconds display differ from someone else's phone?
Because you are comparing two independent device clocks. Both sync to network time, but they check at different moments and network delay differs, so a gap of a second or two between two correct devices is entirely normal. For anything where that matters, one screen has to be the reference for everybody.
Does the timer work if I lock my phone?
Usually not for long. Mobile browsers suspend hidden tabs quickly. Keep the screen on for short drills, or use the device's own timer for anything longer than a few minutes.