Millisecond precision — a clear readout down to hundredths of a second.
Free Online Stopwatch
Start, lap and reset a precise stopwatch — no download, no sign-up.
Online stopwatch you can start in one second
This is a free online stopwatch that counts up from zero so you can measure exactly how long anything takes — a workout set, a study block, a phone call, or a quick task at work. There is nothing to install and nothing to set up: open the page, press Start, and the time runs in your browser.
No sign-up, no ads and no paywall. Record laps and splits, switch to a big fullscreen display, get an audible beep at the interval you choose, and export your laps to CSV when you are done. Your time and laps are even saved in your browser, so a reload won't lose your place.
How to use the online stopwatch
Three buttons do almost everything. You can run the whole stopwatch from the keyboard, too.
Start the stopwatch. Press Start (or the Space key) to begin counting up from zero. Press it again to pause, and once more to resume right where you left off.
Record a lap. While it runs, press Lap (or the L key) to capture a lap. Each lap is listed with its split — the time since the last lap — and the running total, with your fastest and slowest laps highlighted.
Reset when you're done. Press Reset (or the R key) to clear the time and laps and start fresh. Reset asks for a quick confirmation so you never lose a session by accident.
Go fullscreen for a big display. Press the fullscreen button (or the F key) for a large, distraction-free readout — perfect for classrooms, presentations and group workouts. Press Esc or F again to exit.
Space start / pause · L lap · R reset · F fullscreen · M mute · C copy
Stopwatch features that matter
Laps and split times — capture every lap with its split and running total.
Interval beep — an audible cue at the cadence you choose, great for HIIT or Pomodoro.
Fullscreen big display — a large, glanceable readout for classrooms and group workouts.
CSV export and copy — send your laps to a spreadsheet or copy them in one click.
Saved across reload — your time and laps stay put if the page reloads.
Keep screen awake — the display stays on while the stopwatch is running.
Works offline — once the page has loaded, it keeps running without a connection.
No install, no sign-up — it's completely free and runs in your browser.
Stopwatch vs. timer: what's the difference?
A stopwatch counts up from zero to measure how long something takes — you use it when you want to know the elapsed time. A timer counts down from a duration you set and alerts you when it reaches zero — you use it to limit time, like a five-minute break or a cooking step. Put simply: reach for a stopwatch when you want to measure time, and a timer when you want to limit it. Need to count down instead? An online timer is the right tool for that job.
Stopwatch
Counts up from zero so you can measure how long something takes. Reach for it when you want to know the elapsed time of a workout, a study block or a task.
Timer
Counts down from a duration you set and alerts you at zero. Reach for it when you want to limit time, like a five-minute break or a cooking step.
Ways to use a stopwatch
Workouts & intervals
Time reps, rounds and rest periods, or run a full HIIT session. Use laps to record each round and the interval beep to mark work and rest without watching the clock.
Studying & focus (Pomodoro)
Run focused study blocks and breaks. Set the interval beep as a checkpoint so you stay on a Pomodoro rhythm — deep focus, then a short reset — without breaking concentration.
Teaching & presentations
Keep classroom activities, quizzes and group tasks on schedule, and time a speech or rehearsal on the fullscreen big display so everyone in the room can see the count.
Labs & precise measurement
Use the sub-second readout for experiments, timed trials and reaction tests where a fraction of a second matters, then export the laps for your notes. Need to read shift times in 24-hour format? Pair it with our military time converter.
Work & billable hours
A stopwatch is fine for timing one quick task. But it only remembers a number — it can't tell you which project or client to bill, it won't turn into a timesheet, and it lives in a browser tab you can lose. If you are timing client work, jot the result into a time card calculator or check it against an overtime calculator — or, better, track the hours where they become billable records automatically.
See What Time Tracking Looks Like Beyond a Stopwatch
A stopwatch measures one task. WebWork tracks all of your work automatically — across projects, tasks and clients — and turns those hours into timesheets and invoices. Book a demo and we'll walk you through it, from clock-in to payroll.
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When a stopwatch isn't enough
A stopwatch is perfect for one quick task. But it only remembers a number — not which project the time belonged to, which client to bill, or where your week actually went, and it lives in a browser tab you can lose. WebWork turns time into something you can use: it tracks work automatically across projects and tasks, keeps a permanent record you can bill from, and turns those hours into timesheets and invoices — from clock-in to payroll. Professional time tracking, starting at $3.99 per user. Browse our time tracking guides to dig deeper.
Try WebWork for FreeTrack More Than Time with WebWork
A stopwatch times a single session. WebWork tracks where time goes across tasks and projects — and turns it into insight.
Automated Time Tracking
Go beyond a stopwatch — track time automatically across tasks and projects.
Explore Time TrackingProductivity Monitoring
Turn timed sessions into insights on focus, output, and how time is spent.
Explore ProductivityTask Management
Attach timed work to tasks and projects so nothing gets lost.
Explore TasksIdle Time Tracking
Automatically separate active work from idle time for accurate totals.
Explore Idle TimeFAQ
Yes — your time and laps are saved in your browser, so a reload or even closing the tab and reopening it keeps counting. But this is browser storage, not a permanent record: clearing your browser data wipes it, and it can't tell you what you worked on or which client to bill. For a record you can bill from, use a dedicated time tracker like WebWork.
It measures elapsed time to a fraction of a second using your device clock, which is reliable for workouts, studying, presentations and general use. For certified scientific or competitive timing, use a calibrated hardware device.
Yes. Press Lap (or the L key) while it runs to capture each lap. The list keeps every lap with its split (time since the last lap) and total, and highlights your fastest and slowest.
Yes — completely free, no sign-up and no download. It runs in your browser.
Press the fullscreen button (or the F key) for a large, distraction-free display — useful for classrooms, presentations and group workouts. Press Esc or F again to exit.
Yes — turn on the interval beep to get an audible cue at a cadence you choose (great for HIIT intervals or Pomodoro), and use the speaker toggle to mute or unmute.
A stopwatch counts up from zero to measure how long something takes. A timer counts down from a set duration and alerts you when it reaches zero. Use a stopwatch to measure elapsed time; a timer to limit it.
Yes — export all laps to CSV (with splits, totals and your session name) for a spreadsheet or timesheet, or copy them to the clipboard in one click.
For a single quick task, yes. But a stopwatch only remembers a number — it can't tell you which project or client to bill, and it won't turn your hours into timesheets or invoices. To track billable work hours properly, WebWork is built for exactly that.
Yes — the display shows hours, minutes, seconds and hundredths of a second, so you get precise readings for intervals, lab trials and timed tasks.