Online Stopwatch
An accurate stopwatch with laps and full screen, right in your browser.
- Never leaves your device
- No sign-up
Quick answer: To use the online stopwatch, click Start. Use Lap to record splits (each lap shows its own time and the total), Pause to stop and Reset to start over. The Full screen button makes the numbers big for presentations and workouts.
How to do it in 3 steps
- 1Click Start.
- 2Record laps whenever you want.
- 3Pause or reset at the end.
Why use Pronto Arquivo
Hundredths of a second
Precision for workouts, track meets and experiments.
Laps
Each lap time and the running total, in a table.
Full screen
Big numbers to project in a classroom or gym.
Keeps going in the background
Time comes from your device's clock, not from counting frames.
Guides
Interval training
Record a lap after each set to compare your times.
Frequently asked questions
How do I use the online stopwatch?
Click Start; use Lap for splits and Reset to start over.
Does it keep running if I switch tabs?
Yes. It uses the system clock, so the time stays accurate.
Is there a countdown timer?
Yes, in the Online Countdown Timer tool.
Does it work on my phone?
Yes, on Android and iPhone, with nothing to install.
