Random Timer

Set a minimum and a maximum, press start, and the timer picks a random duration somewhere between them and hides it. You do not know when it will go off until it does. That uncertainty is the whole point: it stops people pacing themselves, which is useful in games, in training, and in a surprising number of teaching situations. The default range is 30 seconds to 3 minutes; the range can be anything from a few seconds to hours.

• Pass-the-parcel and hot-potato games. Whoever holds the object when the tone sounds is out. A visible timer would let players count; a hidden one keeps it fair.
• Freeze dance and musical statues. Play music, stop at the tone, restart.
• Sports and fitness. Reaction drills where athletes sprint or change direction on an unpredictable signal, closer to real play than a rhythmic whistle. Coaches set 3–10 seconds.
• Dog training. Variable-interval rewards, which behaviour research shows produce the most persistent responses, need an unpredictable timer.
• Classroom cold-calling. "When the timer sounds, whoever is speaking summarises." Keeps everyone listening.
• Writing and brainstorming. Free-write until the tone; the unknown end stops the mind from winding down early.

The duration is drawn from the browser's cryptographic random number generator, uniformly across the range you set, so every second in the range is equally likely and previous runs have no influence on the next. There is no pattern to learn. If you want a rough sense of how long you have been waiting, the stopwatch in another tab will tell you without revealing the target; for a visible countdown, use the plain timer, and for repeated rounds with fixed lengths the interval timer.