Free Online Countdown Timer with Alarm

Set any duration from one second to twenty-three hours and fifty-nine minutes. Use the intuitive up/down arrows to dial in hours, minutes, and seconds, or tap a quick preset button for common durations like 5, 10, 15, 25, or 30 minutes.

Alarm Sounds and Notifications

Choose from fifteen unique alarm tones — all synthesized in your browser with zero file downloads. Options range from a classic bell and gentle chime to meditation bowl, ocean wave, xylophone, and retro game sounds. Enable browser notifications to get alerted even when the timer tab is in the background.

Advanced Features

Enable the last-10-second countdown tick for an audible alert as your timer approaches zero. Turn on “Count up” in Preferences to keep tracking overtime after the countdown finishes — perfect for knowing exactly how long past a deadline you have gone. The repeat toggle automatically restarts your timer, ideal for interval-based activities.

Popular Timer Presets

Quick-start any of these common countdown durations: 1 minute timer, 3 minute timer, 5 minute timer, 10 minute timer, 15 minute timer, 25 minute timer, 30 minute timer, or 1 hour timer.

Countdown Timer FAQ

How do I set a countdown timer online?

Use the up and down arrows to set hours, minutes, and seconds, or tap a quick preset button (1, 3, 5, 10, 15, 20, 25, 30, 45, or 60 minutes). Press Start and the countdown begins immediately with your chosen alarm sound when it reaches zero.

Can the timer keep counting after it reaches zero?

Yes. Enable “Count up” in Preferences and the timer will continue counting upward after reaching zero, showing you exactly how much overtime has elapsed.

Does this timer have a Tabata mode with 20 seconds on and 10 seconds off?

Yes. The Timer tab includes a built-in Interval Timer with a one-click Tabata 20/10 preset that runs 20 seconds of work followed by 10 seconds of rest for 8 rounds. It also includes HIIT 30/30, HIIT 45/15, and Endurance 60/60 presets, plus fully customizable work, rest, and round settings.

Can I use this as a timer with breaks that switches automatically?

Yes. The Interval Timer automatically alternates between work and rest phases with distinct audio cues and visual color changes at each transition. For the standard Pomodoro structure with session tracking and long breaks, use the dedicated Pomodoro Timer tab.

How many alarm sounds does the countdown timer have?

Fifteen alarm sounds: Classic Bell, Digital Beep, Gentle Chime, Urgent Alarm, Morning Birds, Soft Piano, Retro Game, Meditation Bowl, Military Bugle, Church Bell, Heartbeat, Xylophone, Ocean Wave, Radar Ping, and Rooster Call. Preview any sound before selecting it.

What happens if I close the tab while the timer is running?

The timer will stop and the alarm will not fire. Browser-based timers require the tab to remain open. Pin the ScreenTimer tab in your browser so it stays open while you work in other tabs.