Stopwatch tools · Laps & training
Swimming Split Stopwatch
From the first push-off to the final touch.
Ready when you are
Current lap · 00:00.00
Ready when you are.
Reset this session and remove its recorded marks? Export first if you want to keep them.
Your results
Completed marks appear here. Add a note to remember the details.
A fresh start. Your first mark goes here.
How to use the swimming split stopwatch
Choose pool length and meters or yards, then choose how many lengths each mark represents. Press Record split at the wall touch you are timing. One length means one trip from one end of the pool to the other.
If you time from one end of a 25-meter pool and mark each return, choose two lengths per mark: each split is 50 meters. Pace per 100 uses the same unit as the pool. Rest is included unless you pause. The tool does not detect lengths or strokes automatically.
Does a lap mean one length or two?
People use lap differently, so this tool asks explicitly for lengths per mark. A 25-yard pool with two lengths per mark records 50 yards each time. Changing pool settings requires resetting the current session so earlier distances remain consistent.
How accurate is the stopwatch?
The display can show hundredths of a second, but human reaction and browser input latency affect a manual measurement. Live timing uses a monotonic clock, so changing the device time does not change an open session. After a refresh, recovery uses saved device timestamps. Device sleep and a changed clock can affect that recovery. Keep this page and device awake for dependable timing.
Where are my results saved?
Only in this browser on this device, with no account required. Use one tab per tool to avoid overwriting the same saved session. Export CSV before clearing local settings. Each session can hold up to 500 marks and seven days of active elapsed time. Live updates stop while paused; no stopwatch readings are sent to our server.