⏰ iAlarmClock

Free Online Alarm Clock, Timer, Stopwatch & World Clock

Four time tools in one place. No signup, no ads in your face, no download. Open it, use it, close it.

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Your local time
Set an Alarm Start a Timer

Tools

⏰

Alarm Clock

Set one or many alarms with custom labels. Persists across sessions.
⏱

Countdown Timer

Set any duration or pick a preset (1, 5, 10, 15, 30, 60 min).
⏲

Stopwatch

Centisecond precision. Lap times with best/worst highlighted.
🌍

World Clock

Live time in 12+ cities — London, NYC, Tokyo and more.

World clock — popular cities right now

Live local time in major cities around the world. Click any card for sunrise, sunset, business hours and more.

London
United Kingdom · GMT/BST
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New York
USA · EST/EDT
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Los Angeles
USA · PST/PDT
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Paris
France · CET/CEST
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Berlin
Germany · CET/CEST
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Dubai
UAE · GST
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Mumbai
India · IST
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Singapore
Singapore · SGT
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Hong Kong
Hong Kong · HKT
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Tokyo
Japan · JST
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Sydney
Australia · AEST/AEDT
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São Paulo
Brazil · BRT
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See all cities →

Why iAlarmClock?

🚀

Loads instantly

One small HTML file. No bloated framework, no tracking pixels, no ads.

🔒

Private by design

Everything runs in your browser. Your alarms never leave your device.

📴

Works offline

After your first visit, the app is cached. Use it on a plane.

📲

Add to home screen

Install as a Progressive Web App for one-tap access from your phone.

🎯

No signup, ever

No accounts, no email, no permissions you don't actually need.

🌗

Light & dark

Automatically matches your system theme. Easy on the eyes day and night.

Frequently asked questions

Will the alarm ring if I switch tabs or lock my phone?
The alarm uses your browser's audio engine, so it will ring as long as the tab stays open. To make sure it sounds even with the screen off, keep the tab unmuted, allow notifications, and keep the device plugged in. Browsers may suspend background audio after long idle periods — for critical wake-ups always set a phone alarm as backup.
Is iAlarmClock really free?
Yes. 100% free, no signup, no email required, no download. Just open the page.
Do I need to install anything?
No. It runs in any modern browser. You can optionally "Add to home screen" to install it as a Progressive Web App for one-tap access.
Are my alarms saved if I close the tab?
Yes. Alarms are stored locally in your browser. They'll be there next time you visit on the same device and browser. Nothing is sent to a server.
Can I use it offline?
Yes. After your first visit, a service worker caches the app so it works without an internet connection.
What time zones does the world clock support?
All IANA time zones via your browser's built-in Intl API. We have dedicated pages for 12 popular cities, but any time zone in the world works.