Free Stopwatch Online
Free Stopwatch Online is a free online tool by US AI. With lap times. It runs completely in your browser — no signup, no download, works on mobile and desktop.
📖 How to use
- Press Start to begin timing, Pause to hold it, Lap to record split times and Reset to clear everything.
- Open the tool with the button above — it loads instantly.
- Your work stays on your device; nothing is uploaded anywhere.
✨ Why use this tool?
US AI's free stopwatch online is fast, private and 100% free forever. Bookmark this page and share it with anyone who needs it.
⏱️ What is a stopwatch used for?
A stopwatch is one of the simplest and most useful timing tools. Runners and athletes use it to time laps, sprints and training intervals, comparing each round to get faster. Students use it for focused study sessions and practice exams, keeping track of exactly how long each section takes. In the kitchen, it is perfect for timing recipes — boiling eggs, baking, or resting dough. HIIT and gym workouts rely on precise interval timing for work and rest periods. Speakers and teachers use it to rehearse presentations and keep lessons on schedule. Because our stopwatch shows milliseconds and records unlimited lap times, it works for everything from a 30-second plank to a full marathon training run — all free, private and right in your browser.
Need a timer that counts down instead? Try our free Countdown Timer or the Pomodoro Timer for focused work sessions.
❓ Frequently Asked Questions
Is the stopwatch accurate?
Yes. The stopwatch uses your browser's built-in high-resolution timer and displays time down to milliseconds. It is accurate enough for workouts, study sessions, cooking and everyday timing.
Do I need to create an account or download anything?
No. The stopwatch runs entirely in your browser. There is no signup, no app to install and no download — just open the page and press Start.
Can I record lap or split times?
Yes. Press the Lap button while the timer is running to record each split. Lap times are listed below the display so you can compare every round.
Does it work on my phone?
Yes. The stopwatch works on mobile and desktop browsers. The buttons are touch-friendly, so you can start, pause and record laps with one tap.
Does it work offline?
Yes. Once the page has loaded, the timer itself runs with local code in your browser, so it keeps working even if your internet connection drops.
Will my timing data be uploaded anywhere?
No. Everything happens on your own device. Your start times, pauses and lap records are never sent to any server.