Stopwatch & Timer
Track time with lap recording or set countdown timers
Lap Times
| Lap | Split | Total |
|---|
Quick Presets
This stopwatch and countdown timer does two jobs in one page: a precision stopwatch that records lap splits, and a countdown timer with an audible alert and quick presets. Both run entirely in the browser, work offline, and need no installation. It is useful for timing workouts, cooking, study sessions, talks, and anything else where a phone timer is inconvenient and an ad-covered timer site is annoying.
How to Use
- Choose a mode with the Stopwatch or Countdown timer tab.
- In stopwatch mode, press Start to begin, Lap to record a split, and Reset to zero everything. Each lap appears in a table with its split and the cumulative total.
- In timer mode, set minutes and seconds or tap a preset (1, 3, 5, 10, 15, 30, or 60 minutes), then Start. A beep plays when the countdown reaches zero.
- Switch modes freely. The two run independently, so a running stopwatch is not disturbed by setting up a countdown.
Stopwatch vs Timer: When Each Fits
The distinction is simple but worth stating: a stopwatch counts up and answers “how long has this taken?”, while a countdown timer counts down and answers “tell me when this is over.” Workouts and races usually need the stopwatch because you want the split record afterward; cooking, rest intervals, and presentations need the countdown because the end point is what you are waiting for. If you find yourself starting a stopwatch and watching the clock to know when to stop, you wanted a timer.
Worked Examples
Example 1 — interval training. Six rounds of 40 seconds hard, 20 seconds easy. Use the countdown with a 40-second setting for the work interval, restart it at 20 for recovery, and use the stopwatch separately to record each round’s split if you want a pace history. Because the beep fires in the background, you can set the phone down and keep moving.
Example 2 — a conference talk. Speakers routinely overrun. Start the stopwatch when you begin and place the device where you can see it; if your slot is 10 minutes with questions, a countdown set to 8 minutes gives a two-minute buffer. Practicing with the same timer beforehand makes the pacing instinct reliable.
Example 3 — Pomodoro-style study. Set the countdown to 25 minutes, work on one task, then take 5 minutes when it sounds. The dedicated Pomodoro timer automates the full cycle, but the manual approach is fine for a single session and avoids switching pages.
Split and Total: Reading the Lap Table
Each entry in the lap list has two numbers. The split is the time for that lap alone; the total is the running time since start. Keeping them straight changes how you read a run: a split that grows while the total climbs steadily means you are slowing down, which a total-only glance would hide. When lapping by hand, tap exactly at the boundary — the recorded split includes your reaction time, so consistency of tap timing matters more than absolute precision.
Accuracy, Background Tabs, and Device Sleep
The tool computes elapsed time by subtracting timestamps from the system clock rather than accumulating a counter every 100 milliseconds. That design matters because browsers throttle background tabs to save power: a naive counter would run slow the moment you switched away. Reading the clock keeps the result correct regardless of throttling, and it also handles the case where the device slept mid-timing — the elapsed time is still right when you return. The one caveat is that changing the system clock while a timer runs will shift the reading, which is why countdowns are best started right before use.
Common Mistakes
- Lapping twice by accident. A double tap creates a near-zero split and muddies the table; reset and restart if it happens.
- Timing in the background without starting audibly. The first click on the page also unlocks audio. Start the timer with a click rather than via a script or a restored session, or the beep may be suppressed.
- Using a stopwatch where a countdown belongs. If you keep checking a running stopwatch to decide when to stop, switch to countdown mode.
- Forgetting that reload clears state. Note the result before leaving the page; there is no history kept by design.
- Muting the device. The alert respects the system volume; a muted phone will not announce the end of a countdown.
Features
- Precision stopwatch with lap recording in split and total form
- Countdown timer with audible completion alert
- Quick presets: 1, 3, 5, 10, 15, 30, and 60 minutes
- Accurate across background tabs and device sleep
- Works offline, no account, no installation
- Clean, large display readable at a glance
Related Tools
Frequently Asked Questions
Does the stopwatch keep running if I switch tabs?
Yes. Elapsed time is calculated from the system clock rather than by counting ticks, so the display catches up correctly when you return to the tab. Browsers throttle background timers, which is why counting ticks would drift — reading the clock avoids that problem entirely, and accuracy is preserved even across a device sleep.
What is the difference between split and total time in the lap list?
The split is how long the current lap took, measured from the previous lap. The total is the accumulated time since you started the stopwatch. For interval training the split is what matters, because it shows each interval's pace; for a race the total is the result and the splits show where time was gained or lost.
Can I use the countdown timer for intervals?
Yes, though for repeated intervals the Pomodoro timer is more convenient because it cycles automatically between work and rest. The countdown here is best for a single block — a rest period, a cooking time, or a speaking slot. It provides 1, 3, 5, 10, 15, 30, and 60-minute presets and a custom minutes/seconds entry.
Will I hear the timer if the tab is in the background?
The alert plays through the Web Audio API, so it sounds even when the tab is not focused, as long as the device is not muted and the audio context was unlocked by an earlier click on the page. Start the timer with a click and the audible alert will fire reliably in the background.
Why does my lap time look odd for very short laps?
Human reaction time is around 200 milliseconds, so tapping Lap repeatedly produces laps that include your reaction error. For intervals shorter than a few seconds, an automated timer is more accurate than manual lapping.
Do the times survive a page reload?
No — reloading or closing the page resets everything, because the state is kept in memory to avoid leaving data behind. Keep the tab open while you time something, or note the result before navigating away.
Reviewed by the HandyTools Hub team · Last updated