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alarm-clock

A browser-based alarm clock runs in any tab and rings at a chosen time — useful when your phone is on silent, when you're at a desktop computer, or when you want a backup alarm visible on a separate screen. The ZTools Alarm Clock supports multiple alarms, custom sound choice (ten built-in tones plus upload-your-own), snooze, fullscreen display, and sticky tab notifications so the alarm fires even when the tab is in the background. Runs entirely client-side; no signup, no account.

Use cases​

Backup alarm at your desk​

Phone on silent during a meeting; alarm clock in a browser tab catches you when the meeting runs over.

Cooking / baking timer​

Set an alarm for when bread comes out of the oven. More reliable than a kitchen timer that runs out of battery.

Pomodoro reminder​

25 minutes work + 5 minutes break — set an alarm at the end of each cycle. Or use a dedicated Pomodoro timer.

Wake-up alarm on a hotel laptop​

No phone charger; laptop is your only device. Alarm clock in a browser tab works.

How it works​

  1. Set time — Pick the alarm time. Multiple alarms supported.
  2. Pick sound — Built-in tones (gentle bell, classic ring, bird chirp, etc.) or upload your own MP3.
  3. Configure — Snooze duration (default 5 min), repeat (one-time or daily).
  4. Activate — Browser uses Web Audio API to play sound. Notification API surfaces a desktop notification when the alarm fires.

Examples​

Input: Alarm at 7:30 AM, gentle bell, snooze 5 min

Output: Browser plays sound at 7:30. Snooze button delays by 5 min; second snooze re-triggers.

Input: Multi-alarm: 9:00, 12:00, 17:00 (workday milestones)

Output: All three trigger throughout the day. Each labelled.

Frequently asked questions​

Will it ring if the tab is in the background?

Modern browsers throttle background tabs — alarms fire but with a few seconds delay. For mission-critical wakeups, keep the tab in the foreground or use your phone.

What if I close the tab?

Alarms don't persist past tab close. The tool isn't a daemon — it's a browser tab.

Notification permission?

Optional. Without it, alarm still fires sound; with it, you also get a desktop notification.

Privacy?

All in browser. Alarms / sounds never uploaded.

Tips​

  • For background reliability, keep the tab in the foreground — most browsers throttle non-foreground tabs.
  • Custom sound? Upload an MP3 — the alarm uses your file via local URL, never uploads it anywhere.
  • For Pomodoro, multiple alarms work — but a dedicated Pomodoro timer is more ergonomic.
  • Don't rely on this for medication reminders or critical wake-ups — phone alarms are more robust.

Try it now​

The full alarm-clock runs in your browser at https://ztools.zaions.com/alarm-clock — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-06 · Author: Ahsan Mahmood · Edit this page on GitHub