300 Second Timer — Online Countdown

What is the 300 Second Timer?

The 300 second timer is a free online countdown timer preset to 5 minutes. Just press Start and it counts down to zero, then plays an alarm and shows a notification — even if you have switched to another browser tab. There is nothing to install. Five minutes is the all-rounder: a soft-boiled egg, a short meditation, a focused break between tasks, a kids' time-out, or a warm-up before a workout.

How to set a 300 second timer

1. This page is already set to 5 minutes — or change it in the "Set your own" boxes and press Set.
2. Press Start to begin the countdown. Use Pause to hold it, or Reset to start over.
3. Add time on the fly with +1 min / +5 min, or trim it with −1 min.
4. When it reaches zero you will hear the alarm and get a notification. Choose the sound, repeat and what happens on zero under Timer options.

Timer features

• Alarm sounds — beep, chime, bell or digital, with an optional repeat until you stop it.
• Desktop & phone notification the moment time is up.
• Runs in the background — the remaining time shows in the browser tab while you work elsewhere.
• Fullscreen mode for a big, across-the-room display — great for classrooms, workouts and streams.
• On-zero options — stop, auto-restart (loop), or roll into a stopwatch.
• Free, no download, no sign-up — it works entirely in your browser.

More timers

Set a timer for 1 minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 45 minutes or 60 minutes — or use the online stopwatch and the 1 hour timer.

Frequently asked questions