Online Countdown Timer with Fullscreen & Custom Sounds

How to Set a Countdown Timer

Setting a countdown takes seconds. Enter your desired time in the Hours, Minutes, and Seconds fields at the top of the timer, or tap one of the quick-preset chips (1 min, 5 min, 10 min, 25 min, etc.). Then click Start to begin the countdown. The progress bar beneath the display shrinks in real time so you can see at a glance how much time remains. When the timer reaches zero, your chosen alert sound plays automatically.

Step-by-Step Instructions

1. Set your time. Type directly into the Hours, Minutes, or Seconds fields, or click a preset chip for common durations.
2. Choose a sound. Select from Beep, Bell, Chime, Alarm, or None using the Sound dropdown.
3. Enable auto-repeat if you want the timer to loop - Useful for repeated work intervals or class transitions.
4. Click Start (or press Space) to begin the countdown. The display switches to the countdown view automatically.
5. Click Pause at any time to freeze the timer, then Start again to resume from where it stopped.
6. Click Fullscreen (or F) to expand the timer to your full screen - Ideal for classrooms and presentations.
7. Click Reset to stop and return the timer to the set duration, ready to start again.

Use Cases by Duration

The best countdown duration depends entirely on what you're timing. A 1-minute timer suits rapid-fire quiz rounds; a 25-minute timer matches the classic Pomodoro focus block. Use the table below to find the most effective duration for your situation.

Duration	Best For	Tips
30 seconds – 1 minute	Quiz rounds, quick tasks, transitions	Use the Bell sound so participants hear when time is up without watching the screen
3 minutes	Soft-boiled eggs, short breaks, push-up sets	Pair with the auto-repeat loop for back-to-back intervals
5 minutes	Presentation sections, cooking breaks, warm-ups	Start with 5 min remaining in a meeting segment to give a visible wrap-up cue
10 minutes	Group work, study sprints, hard-boiled eggs	Display in fullscreen on a classroom projector so every student can see
25 minutes	Pomodoro focus blocks, exam sections	Follow with a 5-minute break; the dedicated Pomodoro timer automates this cycle
1 hour	Exams, long meetings, cooking roasts	Use the progress bar to gauge halfway points; the bar visually signals urgency as it shrinks
2+ hours	Long exams, endurance events, all-day workshops	Use the Hours field; consider pairing with an egg timer for sub-sessions

Most Popular Countdown Durations

The 25-minute Pomodoro interval is the single most popular countdown duration, reflecting the widespread adoption of structured focus techniques. Short 5-minute timers are common across cooking and classroom use, while 10-minute and 1-hour timers cover exam and meeting scenarios. The exam timers page has specialist tools for invigilators.

Countdown vs Stopwatch: Key Differences

Both tools measure time, but they suit different workflows. If you need to know how long something has taken, use the stopwatch. If you need an alert when a fixed time period expires, use this countdown timer. The table below lays out the key functional differences.

Feature	Countdown Timer	Stopwatch
Direction	Counts down to zero	Counts up from zero
Alert on completion	Yes - Plays chosen sound	No - Runs indefinitely
Progress indicator	Shrinking progress bar	Not applicable
Auto-repeat / loop	Yes - Toggle on/off	Manual reset only
Split recording	Not available	Yes - Lap feature built in
Primary use	Cooking, studying, exams, classes	Sports, performance measurement

Frequently Asked Questions

Can I set a countdown for more than an hour?

Yes. Use the Hours field to set countdowns up to 99 hours. You can also type directly into any of the hour, minute, or second fields.

Can I set the timer to ring an alarm?

Yes. Choose from Beep, Bell, Chime, or Alarm in the Sound dropdown before starting the timer. The selected sound plays automatically when the countdown reaches zero. If you want the alarm to repeat on a loop, enable the Auto-repeat toggle.

Does the countdown timer loop automatically?

Yes - Enable the Auto-repeat toggle before starting. The timer will play its alert sound and immediately restart from the beginning. For alternating work/rest intervals of different lengths, try the interval timer instead.

Can I set a countdown for custom hours, minutes, and seconds?

Yes. Type any value into the Hours (0–99), Minutes (0–59), and Seconds (0–59) fields. You can mix them freely - 1 hour 15 minutes 30 seconds is H:1 M:15 S:30.

Can I use this countdown timer for classroom exams?

Yes. Set your exam duration, click Fullscreen, and the countdown fills the entire projector screen. For dedicated exam management, see the exam timers page. Teachers can also explore the full classroom timers collection.

Will the sound play if I switch to another browser tab?

On desktop browsers the alert sound will typically play from a background tab. On mobile, browsers may throttle background tabs - Keep the tab visible and your screen unlocked for reliable alerts.

More Timer Tools

The countdown timer is one of many timing tools available here. The Pomodoro timer automates the 25-minute focus plus 5-minute break cycle. The egg timer has pre-set cooking durations for soft, medium, and hard-boiled eggs. The classroom timers page collects teacher-specific tools including visual and sand timers. For exam invigilators, the exam timers page adds warning alerts and larger display options. And for a full stopwatch with lap recording, visit the main stopwatch. For use-case guides, see the dedicated pages for meetings and standups, classroom timing, and kitchen and cooking timers.