Online Alarm Clock
Set multiple alarms with snooze functionality. See also our Timer, Countdown Timer, and Time Calculator.
How to Use the Alarm Clock
Set the hour (0-23) and minute (0-59) for your alarm, optionally add a label, then click Add Alarm. The alarm will trigger when the current time matches your set time, playing an audio tone. Dismiss the alarm or hit Snooze to delay it by 5 minutes. Toggle alarms on/off with the checkbox or delete them entirely.
Features
- Set unlimited alarms with custom labels
- Enable/disable individual alarms with toggle
- Audio alert using Web Audio API
- 5-minute snooze functionality
- Shows time remaining until each alarm
- Live clock display updating every second
- Dismiss or snooze ringing alarms
Alarm Tips
Set multiple alarms as backup wake-up calls spaced 5-10 minutes apart. Use descriptive labels like "Meeting at 2 PM" or "Take medication" to remember why you set each alarm. The snooze feature automatically adjusts the alarm forward by 5 minutes. Keep this tab open for alarms to work — they rely on the browser being active.
For productivity, set alarms at regular intervals throughout your workday to remind you to take breaks, stretch, drink water, or switch tasks. The time-remaining display helps you gauge how long until your next alarm without doing mental math.
When using the alarm for cooking, set separate alarms for different stages of preparation. Label each alarm with the specific action needed (e.g., "Check oven", "Add pasta", "Remove from heat"). The enable/disable toggle lets you prepare alarms in advance and activate them only when needed.
The snooze feature is designed to give you 5 additional minutes before re-alerting. This mimics traditional alarm clock behavior where a short delay helps you transition from one state to another without being jarred by an immediate repeat alarm. Snoozed alarms are marked with an indicator so you can track which alarms have been postponed.
Reference Table
| 24-Hour | 12-Hour | Common Use |
|---|---|---|
| 06:00 | 6:00 AM | Early morning wake-up |
| 07:30 | 7:30 AM | Standard work morning |
| 12:00 | 12:00 PM | Lunch reminder |
| 14:00 | 2:00 PM | Afternoon meeting |
| 17:00 | 5:00 PM | End of work day |
| 22:00 | 10:00 PM | Bedtime reminder |
Frequently Asked Questions
Will the alarm work if I close the browser tab?
No, the alarm requires the browser tab to remain open. The JavaScript timer stops when the tab is closed. Keep the tab open for reliable alarm functionality.
Why is there no sound when the alarm triggers?
Browsers require user interaction before playing audio. Click anywhere on the page first. Also ensure your device volume is turned up and not muted.
Can I set alarms for specific dates?
This tool sets daily recurring alarms based on time only. For date-specific reminders, use the alarm time closest to your event and set it on that day.
How does snooze work?
Pressing Snooze dismisses the current alarm and creates a new alarm 5 minutes later. The snoozed alarm is marked with an indicator so you can track it.
Is 24-hour format supported?
Yes, you set alarms in 24-hour format (0-23 hours). The display shows the time in 12-hour AM/PM format for easy reading.
Can I use this as a wake-up alarm?
Yes, but remember your computer must be awake and the browser tab must be open. It works well for nap alarms or reminders during work, but for morning wake-up calls a physical alarm clock or phone is more reliable.
Related Tools
About Online Alarm Clocks
Online alarm clocks have become popular alternatives to physical alarm clocks, especially for office workers and students who spend long hours at their computers. While they lack the reliability of dedicated hardware (since they depend on browser and computer being active), they offer convenience for daytime reminders, meeting alerts, and productivity timing.
The Web Audio API used by this tool generates alarm sounds entirely in the browser without needing pre-recorded audio files. By creating an OscillatorNode and connecting it to a GainNode, we produce a clear, attention-getting tone that works across all modern browsers. The square wave oscillator type produces a distinctive buzzing sound similar to traditional alarm clocks.
Browser notification permissions and autoplay policies can affect alarm functionality. Modern browsers require user interaction before playing audio to prevent websites from making unexpected sounds. This is why clicking anywhere on the page before setting your alarm ensures the audio context is ready to produce sound when the alarm triggers.
For professionals who work across time zones, setting alarms for specific times helps coordinate with international colleagues. Set an alarm for a call scheduled in a different time zone, and the countdown display shows exactly how long until the meeting starts. This prevents the mental math errors common with time zone conversions.
Alarm fatigue is a real phenomenon where people become desensitized to frequent alerts. In healthcare settings, excessive alarms can lead to critical alerts being missed. For personal use, set alarms only for truly important events and use the label feature to distinguish between urgent and routine reminders at a glance.
The Web Audio API square wave used for the alarm creates a distinctive sound that cuts through background noise better than a pure sine wave. The frequency of 660 Hz was chosen because it falls in the range where human hearing is most sensitive (1-4 kHz), ensuring the alarm is noticeable even at lower volume levels. Different browsers may handle audio slightly differently, but the Web Audio API provides consistent cross-browser behavior for tone generation.