30 Second Timer — Free Half-Minute Countdown
Free online countdown — fullscreen, alarm, no signup
How to Use This 30 Second Timer
Set Duration
The timer is preset to 30 seconds. Click Set to confirm.
Initialize
Review the countdown display and enter fullscreen if needed.
Start
Hit Start to begin. The alarm sounds when time reaches zero.
Cast This Timer to a Bigger Screen
Mirror this countdown to any TV, projector, or display via Chromecast, AirPlay, or HDMI. Perfect for gyms, classrooms, sports facilities, or game events where everyone needs to see the same countdown.
Full casting guideCommon Uses for a 30 Second Timer
Quick exercise intervals
A standard rest interval in circuit training — short enough to keep your heart rate elevated, long enough to recover for the next set. Display it on the gym monitor so athletes stay on track.
Classroom activity transitions
Give students a 30-second think time or transition window. Project the countdown so every student knows exactly how long they have to prepare their response.
Game show answer countdowns
Run a quick game show round with a visible countdown. Cast it to the main screen so contestants and audience see the same time pressure.
Cooking and kitchen timing
Waiting for a sauce to reduce or timing a quick cooking step. The alarm at zero means you can focus on other prep without watching the clock.
A 30 second timer is short enough to create real urgency but long enough to complete a meaningful task. Whether you're timing a Tabata rest interval in fitness training, giving students a 30-second think time in classrooms, running a quick game show round, or waiting for a sauce to reduce, this timer starts instantly in your browser with no setup needed. The large fullscreen display is easy to read across the room, and when the countdown hits zero an alarm sounds automatically. Thirty seconds is also a standard rest interval in circuit training — short enough to keep your heart rate elevated, long enough to recover for the next set. Need it on a bigger screen? Cast this timer to your TV or projector using Chromecast or AirPlay, and control it from your phone while the countdown shows fullscreen on any display.
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Fun Fact
A typical 30-second Super Bowl advertisement costs over $7 million as of recent years. Breaking this down, that's approximately $233,333 per second of airtime, making it one of the most expensive advertising slots globally. For comparison, a 30-second prime-time TV spot on major networks averages around $100,000-$500,000. The Super Bowl's massive audience (over 100 million viewers) and cultural significance make it a unique platform where the ads themselves become part of the entertainment.