Quick answers
How do I set a 5-minute classroom timer?
Click the 5 min preset (or type 5 in the Minutes field), then press Start. The big display counts down from 05:00 and plays a triple beep when time is up.
Will the timer beep if the tab is in the background?
Yes. The alarm is generated in the browser itself, so it plays even when the tab isn't visible — and the tab title keeps showing the remaining time, so you can monitor it while working elsewhere.
Can I pause and resume the timer?
Yes. Pause freezes the countdown exactly where it is, and Start resumes from that point. Reset returns the timer to the time you set.