Millisecond-precision elapsed time
Stopwatch
A stopwatch counts up instead of down, which makes it the right tool whenever you do not know in advance how long something will take — you just want to measure it. This one runs to millisecond precision and captures laps: press Lap and it records the elapsed time at that instant while the clock keeps running, building a list on screen that stays put for you to read afterward. That covers a wide range of uses — timing sets and rest in the gym, tracking how long each step of a recipe actually takes, timing laps at a track, measuring how much of your day a task really eats, or refereeing a game. Anywhere the question is "how long did that take?" rather than "how much time is left?", this is the mode you want. Using it well is mostly about the laps. A single total time tells you the what; the lap list tells you the why. If you are timing repeated efforts — running laps, drilling a skill, working through a routine — the split captured at each Lap press lets you compare one segment against the next and see where you slow down. The non-obvious tip is to read the laps as a shape, not a column of numbers: a run that starts fast and fades looks completely different from one that holds steady, and the pattern is usually more useful feedback than the final time. Plenty of people discover their real problem is the third rep, not the last. Keyboard shortcuts make it quick under pressure — space starts and pauses, L captures a lap, R resets — so you can keep your eyes on what you are timing rather than hunting for buttons. And because the clock is based on actual elapsed time rather than counting ticks, it stays accurate even if you switch tabs; when you come back, the running time is correct. If you want to hand someone the same setup, the copy-link button captures it in a shareable URL.
Stopwatch
JavaScript is required to run this timer — enable it to start, pause, and hear sound alerts.
Space start/pause R reset L lap F fullscreen
- No laps yet — press Lap (or "l") while running.
Enable JavaScript to see background-alert options — this timer keeps correct time either way, but notifications and the install prompt both require it.
Frequently asked questions
- What does the Lap button do?
- It records the elapsed time at the moment you press it, without stopping the clock. Each press adds an entry to the on-screen list, so you can capture and compare multiple segments — laps of a track, reps of a drill, steps of a process.
- What are the keyboard shortcuts?
- Space starts and pauses, L captures a lap, and R resets. They let you operate the stopwatch without looking, which matters when you are timing something live. Shortcuts are ignored while you are typing in a text field.
- Does it stay accurate if I switch to another tab?
- Yes — the elapsed time is computed from the actual start time, not by counting ticks, so backgrounding the tab does not make it drift. When you return, the displayed time is correct.
- Can I save or share my times?
- The copy-link button captures the stopwatch setup in a URL you can share or reopen. Lap times themselves live on the page while it is open, so note them down if you need a permanent record.
- Is there a sound when I stop it?
- A stopwatch counts up with no set end, so there is no alarm — it runs until you pause or reset it. If you need an alert after a known duration, use a countdown timer instead.
This timer keeps the exact time even if you switch tabs. If this tab or your browser closes, nothing can alert you at the exact finish time — there's no server behind this, by design. Come back any time and we'll tell you honestly how long ago it ended.