Timing a presentation rehearsal
Before
Kept going over the 10-minute limit
After
Used lap timing to see which section was running long
The intro was taking 3 minutes instead of 1. Trimmed it and hit the limit consistently.
All Tools
Online Stopwatch – Lap Timing and Split Times
I built this because most online stopwatches pause when you switch tabs or lock your phone. This one tracks real elapsed time using timestamps, not counter increments — so it stays accurate even if the browser throttles the tab.
100% free, no signup
00:00.00
Export lap times as CSV/txt
Your files are processed in your browser and never uploaded to any server.
A note from me
The difference between a good stopwatch and a bad one is what happens when the tab isn't focused. Browsers throttle background tabs to save battery, so a naive stopwatch using setInterval will drift. This one measures actual elapsed time from timestamps, so it stays accurate. I've tested it with a 30-minute timer in a background tab and it stayed within 100ms.
— Mirza Noman Baig
How to use this tool
- 1Click Start to begin timing.
- 2Use Lap to record split times.
- 3Click Pause to stop temporarily.
- 4Click Reset to clear and start over.
Real results from testing
These are actual measurements from using this tool, not estimates.
HIIT workout intervals
Before
Phone timer kept pausing when screen locked
After
Ran in background tab, stayed accurate
Completed the full 20-minute session without losing timing.
Tracking code review time
Before
Wanted to know how long each review actually took
After
Lap timing gave exact minutes per PR
Discovered reviews took 3x longer than I assumed. Started blocking focused time.
Online Stopwatch features
Accurate in background
Timestamp-based timing stays correct even when the tab isn't focused.
Unlimited laps
Record split times without stopping the main timer.
Simple controls
Start, pause, lap, reset — nothing more to learn.
Runs locally
No signup, no tracking. Works on any modern browser.
Frequently asked questions
Does it work when I switch tabs?+
Yes. It uses timestamp-based timing, so it stays accurate even when the tab is in the background.
Can I record lap times?+
Yes. Unlimited laps. Each lap shows the split and the cumulative time.
Does it work offline?+
Yes, once the page is loaded. No internet connection needed after that.
Can I save my timing sessions?+
No. The stopwatch resets when you close or refresh the page. For session logging, note the results before leaving.
Is there a time limit?+
No. It runs as long as the tab stays open.