Online Stopwatch
Free online stopwatch with laps and split times. Start, pause, reset, and record laps to the millisecond. Keyboard shortcuts included — no download or signup required.
Elapsed Time
Ready
00:00.00
Space = start/pause · L = lap
Frequently Asked Questions
The stopwatch is accurate to the millisecond. It stores a start timestamp and computes elapsed time from clock differences whenever it renders, instead of counting interval ticks — so backgrounded tabs, slow rendering, or timer throttling never cause drift.
A lap records two numbers: the split (time for just that lap, since the previous lap) and the total elapsed time at the moment you pressed Lap. This lets you compare individual segments, like each 400 m of a run or each task in a study session.
Press Space to start or pause the stopwatch and L to record a lap while it is running. Shortcuts are ignored while typing in form fields, so they never interfere with other inputs on the page.
Yes. The stopwatch is a web page that runs entirely in your browser, so it works on any device — desktop, phone, or tablet — with no app to install and no account needed.
Yes. Because elapsed time is derived from timestamps rather than counting timer events, switching tabs or locking your screen does not lose time — when you return, the display shows the correct elapsed duration.
No. The stopwatch persists nothing: times and laps live only in the page memory and disappear on reset or reload. Nothing is uploaded, and there is no signup.
Quick Answer
Press Space or click Start to begin timing. Press L (or the Lap button) to record a lap — each lap shows its split time and the running total. Press Space again to pause, and Reset to clear. Our stopwatch uses performance.now()-based timing, so it stays accurate to the millisecond even if the tab is backgrounded. It runs entirely in your browser — free, with no signup and nothing stored.
Key Facts
- Drift-free timing: elapsed time computed from performance.now() timestamps, not tick counts
- Lap mode records both split time (this lap) and total elapsed time
- Keyboard shortcuts: Space = start/pause, L = lap
- Accurate to the millisecond (displays hundredths)
- Runs 100% in your browser — nothing is uploaded or stored
- Works on desktop, tablet, and mobile with no installation
Frequently Asked Questions
How accurate is this online stopwatch?
The stopwatch is accurate to the millisecond. It stores a start timestamp and computes elapsed time from clock differences whenever it renders, instead of counting interval ticks — so backgrounded tabs, slow rendering, or timer throttling never cause drift.
What are laps and split times?
A lap records two numbers: the split (time for just that lap, since the previous lap) and the total elapsed time at the moment you pressed Lap. This lets you compare individual segments, like each 400 m of a run or each task in a study session.
What are the keyboard shortcuts?
Press Space to start or pause the stopwatch and L to record a lap while it is running. Shortcuts are ignored while typing in form fields, so they never interfere with other inputs on the page.
Can I use this stopwatch on my phone or tablet?
Yes. The stopwatch is a web page that runs entirely in your browser, so it works on any device — desktop, phone, or tablet — with no app to install and no account needed.
Does the stopwatch keep running if I switch tabs?
Yes. Because elapsed time is derived from timestamps rather than counting timer events, switching tabs or locking your screen does not lose time — when you return, the display shows the correct elapsed duration.
Is my data saved anywhere?
No. The stopwatch persists nothing: times and laps live only in the page memory and disappear on reset or reload. Nothing is uploaded, and there is no signup.
Elapsed Time
Ready
00:00.00
Space = start/pause · L = lap