About Online Stopwatch
Key takeaways
- Online Stopwatch is a free manual stopwatch that counts up from zero, with lap and split times, full screen, a classroom view, CSV export and up to 20 saved sessions.
- It runs in your browser. Your times and laps are never uploaded.
- It is run by Takreparation Skåne AB in Ängelholm, Sweden. Some pages show ads, which keep it free.
What is Online Stopwatch?
Online Stopwatch is a free stopwatch for practice runs, presentations, kitchen tasks, lessons and quick comparisons. You press Start, mark laps with Lap or the L key, and pause or reset when you are done. There is no account, no setup and nothing to install. After your first visit it also opens without a connection.
Which stopwatch modes are there?
| Mode | Best for | What is different |
|---|---|---|
| Stopwatch | Everyday timing | Laps appear once you record one |
| Lap stopwatch | Repeated attempts | The lap table is always shown, with fastest, slowest and average after two laps |
| Fullscreen stopwatch | Reading the time across a room | Large display, F to open full screen, Escape to leave |
| Classroom stopwatch | Lessons and experiments | Hundredths hidden by default; results shown only when you turn on Show results |
All four use the same timing engine, so a time means the same thing in every mode.
How does it measure time?
It counts with your browser's steady clock (performance.now), which is not affected by changes to the wall clock. It also checks the wall clock. If the two drift apart by more than two seconds, for example because the device went to sleep, the stopwatch keeps the larger estimate and shows a warning so you can check your results. The highest time it can show is 999:59:59.99.
What can it not do?
Manual timing depends on your reaction, your device and your browser. Hundredths on the display are not a promise of hundredth-second accuracy. The stopwatch does not replace certified competition timing, and it times one session at a time, not several people at once.
Who runs Online Stopwatch?
onlinestopwatch.dev is run by Takreparation Skåne AB, Sparvgränd 6, 262 41 Ängelholm, Sweden (org.nr 556988-5931, VAT SE556988593101). CEO: Flemming Harboe Olsen. Flemming Olsen is a Swedish small-business owner who builds free web tools, and onlinestopwatch.dev is one of them. Contact: info@onlinestopwatch.dev or +46 760 061 969, or see the contact page.
How is the site paid for?
Some pages show ads from Google AdSense, which keeps the stopwatch free. Ads are kept away from the display and its buttons. In the EEA, the UK and Switzerland you are asked for consent before ad cookies are used. Change your choice under "Privacy and cookie settings" at the bottom of every page. See the privacy page.
Frequently asked questions
Does the stopwatch keep running if I switch tabs? Yes. Time is measured from the clock, not by counting screen updates, so it keeps counting while the tab is in the background. The display catches up when you come back.
Need a countdown instead? Our sister site Online Timer counts down with an alarm, also free and without an account.