Fullscreen Clock Tutorial
Detailed guide, best practices, and FAQ
Use Cases
The fullscreen clock is ideal for countdowns in presentations, meeting time management, classroom exams, Pomodoro, live-stream backgrounds, and sports training. No app install needed — runs in the browser with one-click fullscreen.
Features
- Three modes: System time (live clock) / Stopwatch / Countdown
- One-click fullscreen: large digits for projection and viewing from a distance
- Clock mode: 12/24-hour toggle, optional seconds, optional date with weekday
- Stopwatch: centisecond precision, lap timing, lap list (total + split)
- Countdown: hours/minutes/seconds input, progress bar, triple beep at zero
- Pause/Resume: supported for both stopwatch and countdown
- Local: no network needed, runs entirely in the browser
Examples
Example 1: Scenario 1: Meeting countdown — switch to Countdown, set 15:00, fullscreen to projector; beeps at zero to end.
Example 2: Scenario 2: Exam timing — switch to Clock mode with 24-hour + seconds + date, fullscreen for students to track progress.
Example 3: Scenario 3: Sports training — switch to Stopwatch, lap each circuit for running or HIIT.
Example 4: Scenario 4: Pomodoro — switch to Countdown, 25:00 focus / 5:00 break, repeat.
Best Practices
- Before projecting, exit browser fullscreen (F11) first, then use this tool's fullscreen button to avoid conflicts
- Keep countdowns under 1 hour; for longer sessions use a dedicated Pomodoro tool
- Beeps use Web Audio API; needs audio permission — muted tabs will be silent
- Press ESC to exit fullscreen (same as browser native behavior)
FAQ
How do I exit fullscreen?
Press ESC or click "Exit Fullscreen". Fullscreen is managed by the browser, behaves like native fullscreen.
Does countdown beep at zero?
Yes, three 880 Hz beeps. Note: muted browser tabs will be silent; first playback may require prior user interaction (browser autoplay policy).
What's the stopwatch precision?
Centisecond (1/100 s), refreshed at 20 Hz. Sufficient for most timing scenarios but not professional race timing.
Does the timer persist after closing the browser?
No. State is in memory; refresh or close the page and it's lost. For long-term tracking use the dedicated Pomodoro tool.