Online Timer & Stopwatch — Countdown with Alarm
A free online countdown timer with an alarm, plus a stopwatch with lap times. Presets for 1 to 60 minutes, fullscreen mode, and it keeps accurate time in a background tab.
05:00
Tip: press Space to start and pause.
Quick start
A timer and a stopwatch in one
Use the Timer to count down from any time up to 99 hours, or tap a preset to start straight away. Use the Stopwatch to measure how long something takes, with lap times for intervals, rounds or splits. Both run entirely in your browser, with nothing to install and no account.
Popular ways to use it
- 25-minute focus sessions — the Pomodoro technique alternates 25 minutes of focused work with a 5-minute break.
- Cooking — eggs, pasta, rice and tea all run on a timer.
- Classrooms and meetings — put the countdown in fullscreen on a projector so everyone can see the time left.
- Workouts — use the stopwatch's laps to time intervals, rounds or rest periods.
- Presentations — keep a talk within its slot without checking your phone.
Why this timer stays accurate
Many online timers count a tick every second. Browsers deliberately slow those ticks down in background tabs to save battery, so a tick-counting timer falls behind the moment you look away. This one records when it was started and compares that with the real clock on every update, so it is right to the second whether or not you're watching it.
Keyboard and fullscreen
Press Space to start or pause without reaching for the mouse. Fullscreen fills the screen with just the clock, which makes it readable from across a room.
Frequently asked questions
Will the timer keep running if I switch tabs?
Yes. It works from the actual clock time rather than counting ticks, so it stays exact even when your browser slows down background tabs. The remaining time also shows in the tab's title, and the alarm plays when it reaches zero — as long as the tab stays open.
Why didn't I hear the alarm?
Check that “Play an alarm” is ticked, that your device isn't muted, and that the tab is still open. Browsers only allow a page to make sound after you've interacted with it, which is why the sound is unlocked when you press Start.
Does it work on my phone?
Yes, but phones are stricter than computers: if the screen locks or you switch apps, the browser may pause the page completely. For a timer you need to rely on while your phone is locked, use the phone's built-in clock app.
How accurate is the stopwatch?
It displays hundredths of a second and measures from your device's clock, so over minutes or hours it doesn't drift. Button presses themselves carry a small human reaction delay — typically 0.15–0.25 seconds — which no stopwatch can remove.
Related tools
Percentage Calculator
Five percentage modes, from tips and discounts to percent change.
Open toolDays Between Dates
Count calendar days and Monday–Friday business days between dates.
Open toolQR Code Generator
Make QR codes for links, Wi-Fi and text. PNG or SVG, never expires.
Open toolLast updated September 25, 2026