Online stopwatch with laps, fullscreen
An online stopwatch puts the running time in digits you can read from across the room, with laps beside them. Leave it on an iPad or a spare screen while you time a race, a drill, or a task.
How to use
The digits start at zero. Press Start, or the space bar, to run the watch, and press the same control to stop. While it runs, Lap records the total so far and the time since the previous lap. The newest lap sits at the top. After two laps, the fastest split uses the second accent colour and the slowest is muted. Stop, then Reset, clears the time and the list. Copy laps puts the table on the clipboard as tab-separated columns you can paste into a spreadsheet. The list holds 99 laps.
Set it up on an iPad or second screen
Put an iPad on a stand, or move the window to a second monitor and leave it there. In Safari, tap Share, then Add to Home Screen, and open the page from the new icon so the browser bars stay hidden. The page asks for a wake lock while this tab is open. iPadOS can still sleep, so set Auto-Lock to Never on a device you leave running. For a shared desk, turn on Guided Access under Settings, then Accessibility. At night, lower Dim. Press F for fullscreen on a desktop. Leave burn-in shift on if the panel will show one layout for hours.
Customize it
The table lists every control and the URL parameter that stores it. Change a value and the address bar updates, so a bookmark is a complete setup. Theme, font, scale, dim, and burn-in shift are shared with the other tools on this site. Precision and the lap list belong to this page. Seconds reads 12:34. Tenths adds one decimal, and hundredths adds two. Turning laps off hides the list. Times you already recorded stay saved and return when you show the list again.
| Setting | URL param | Allowed values | Default |
|---|---|---|---|
| PrecisionSeconds shows 12:34. Tenths adds one decimal. Hundredths adds two. | precision | Seconds (s), Tenths (ds), Hundredths (cs) | Hundredths (cs) |
| Show lapsThe list sits beside the digits on a wide screen, and below them on a tall one. | laps | On (1) or off (0) | On |
| Theme | theme | Midnight (midnight), Carbon (OLED) (carbon), Paper (paper), Forest (forest), Dusk (dusk), Ocean (ocean), Aurora (aurora), Terminal (terminal), Graphite (graphite), Porcelain (porcelain) | Midnight (midnight) |
| Font | font | System (sans), JetBrains Mono (mono), Space Grotesk (grotesk), Fraunces (serif), Bebas Neue (condensed), Orbitron (digital), Condensed Bold (flip) | System (sans) |
| Scale | scale | 50–150, step 5% | 100% |
| Dim | dim | 0–80, step 5% | 0% |
| Burn-in shiftNudge the display a few pixels so a static clock does not mark the screen. | shift | On (1) or off (0) | On |
Keyboard shortcuts
These keys work when focus is not in a text field. The shell handles fullscreen, settings, hiding the bars, and this list. This page adds start, stop, lap, and reset. Space starts or stops. L records a lap while the watch is running. R clears the time and the laps from any state. Press the question mark whenever you need the list again.
| Key | Action |
|---|---|
| F | Fullscreen |
| S | Settings |
| H | Hide or show the interface |
| ? | Keyboard shortcuts |
| Esc | Close |
| Space | Start or stop |
| L | Lap |
| R | Reset |
Precision on an online stopwatch
Hundredths and tenths redraw about thirty times a second, which is enough to read a split and quiet enough to leave on a desk. Whole seconds skip that frame loop, and a stopped watch does too. The number is the device clock minus the moment you pressed Start, plus time already banked, so a reload or a sleep does not lose a running watch. A paused watch stays on the time it had when you stopped it. This is a desk display of the system clock, not a timing gate. For a countdown, use the online timer. For focus and breaks, use the pomodoro timer. For the time of day, use the fullscreen clock.
FAQ
How accurate is it?
The hundredths redraw about thirty times a second, so that place steps instead of spinning. The elapsed time comes from the clock on this device, not from counting frames, so a long run stays accurate to a hundredth of a second. Pausing shows the time at the stop. If the computer sleeps while the watch is running, the next look includes that gap. This is a desk display of the system clock, not a lab instrument.
Does it keep running if I reload?
Yes, if it was running when you left. The start time and the banked time are saved in this browser, and reopening the page shows the elapsed time that follows from the clock. A paused watch reopens paused, on the same total, with the same laps. Closing the tab does not freeze a running watch. The page catches up when you return. Clearing site data for this host removes the saved run.
Can I copy the laps?
Yes. Copy laps writes the list as tab-separated text: lap number, lap time, and total, newest first, in the precision on screen. Paste it into a spreadsheet and the columns split on the tabs. The button sits with the list, so it is there when the control bar is hidden. If the browser blocks the clipboard, the page says so. The list also stays in the saved state on this device, up to 99 laps.
Will the screen stay awake?
The page asks for a wake lock while the tab is open, which stops many laptops from dimming. A lock screen, a closed lid, or a short iPad Auto-Lock can still turn the display off. The watch does not need the screen to keep time. When you come back, a running watch includes the time the screen was dark. Set Auto-Lock to Never if the digits should stay visible on a stand.
How is this different from the timer?
The timer counts down to zero and can chime. This page counts up from zero and has no alarm. Use it when the length is not known yet: a speech, a lap, a hold, or a task you stop by hand. Laps mark the points in between without stopping the total. The pomodoro timer is for focus blocks and breaks. The clock is the time of day. This one is the elapsed time, large enough to read across the room.