Set Alarm for 11:00 AM - Free Online Alarm Clock

Wake up refreshed between natural 90-minute REM sleep cycles. If you go to sleep now, optimal wake-up times are:

How to use Alarm Clock?

How Does the Alarm Clock Work?

Basically, the alarm clock works by programming one or more hours so that, when the set time arrives, an alarm sounds. Some clocks and alarm clocks, in addition to ringing the alarm, have the hourly chime feature that serves to notify when the hour has changed.

The alarm clocks have two main functions: to awaken people from their sleep and to work as a reminder to signal a certain event or activity.

The History of the Alarm Clock

The origins of the first alarm clocks are still unknown, but there are reports of the existence of primitive devices with a similar function as early as centuries BC. A great example is that of Plato in ancient Greece. Believe it or not, at that time the philosopher already had a large water clock with an alarm system that made the water sound like an organ. This fact is still not confirmed, nor what motivated the construction of the alarm, but it is believed that it was a device set up to signal the beginning of his lectures at dawn.

In subsequent centuries, alarm clocks were used extensively by religious institutions to announce the time of prayers or other community events. There are also reports of individual, successful attempts at making personal devices, but these were far off and were never patented or sold.

The first user-configurable alarm clock as we know it today was first patented in 1847 by a French inventor. Since then, devices have not stopped evolving. The radio was one of the first devices to incorporate this extra feature, which we know as a clock radio, later on, over time, other devices imposed this functionality.

Why Use an Online Alarm Clock? Benefits, Science & Tips

An online digital alarm clock running in your browser eliminates phone distractions and notification clutter. Built-in audio synthesis and screen keep-awake technology ensure you never sleep through an important meeting, class, or wake-up call.

Reliable Loud Sound & Screen Sleep Prevention

Unlike mobile apps that get silenced by battery saver modes, silent switches, or background app sleep, this online alarm clock leverages the Web Audio API for crisp, penetrating audio and active NoSleep protection to keep your screen awake on your desk or nightstand.

Wake Up Refreshed with Sleep Cycle Timing

Human sleep naturally occurs in 90-minute REM cycles. Waking up in the middle of deep sleep causes grogginess (sleep inertia). Use our built-in Sleep Cycle Calculator above to time your alarms with natural cycle transitions for effortless mornings.

• Multi-Alarm Scheduling: Set up to 5 independent alarms with custom schedules for staggered wake-ups or daily tasks.
• Hourly Chime & Audio Options: Subtle hourly beeps to track time and customized loud siren or gentle bell tones.
• Convenient Keyboard Shortcuts: Hit Spacebar for 5-minute Snooze, Enter to turn off, and C to toggle Chime.

Works 100% Offline Once Loaded

All timing calculations and sound generators run locally within your browser. Even if your internet connection drops overnight, your scheduled alarms will reliably ring right on time.

Discover our suite of browser-based timekeeping tools, chronometers, and specialized market alarms.

Quickly set an alarm for common morning routines, work shifts, or power naps: