Free Online Alarm Clock, Timer & World Clock
Free online time tools — alarms, timers, stopwatch, world clock, and more.
Free Online Alarm Clock, Timer & World Clock
Alarm
Set a wake-up alarm with custom sounds, 12/24-hour display, and fullscreen mode.
Open Alarm Clock →Duration Timer
Set a duration in hours, minutes, and seconds — with stop, restart, or count-up at zero.
Open Duration Timer →Countdown
Count down to a date, time, or upcoming holiday with sound alerts.
Open Countdown →Stopwatch
Track elapsed time with millisecond precision and lap splits.
Open Stopwatch →World Clock
Check the current time in cities around the world.
Open World Clock →Pomodoro
Run focus sessions with automatic work and break cycles.
Open Pomodoro →
More tools
Popular Alarms
Popular Timers
Popular Cities
- London, United Kingdom
- New York, United States
- Melbourne, Australia
- Paris, France
- Sydney, Australia
- Tokyo, Japan
- Dubai, United Arab Emirates
- Singapore, Singapore
- Los Angeles, California
- Chicago, Illinois
- Toronto, Canada
- Berlin, Germany
- Mumbai, India
- Beijing, China
- Denver, Colorado
- Seoul, Korea
- Madrid, Spain
- Moscow, Russia
Common Time Zones
Holiday Countdowns
How it works
Choose a tool
Pick an alarm, timer, stopwatch, world clock, or Pomodoro from the cards above — or jump to a preset time or city below.
Configure it
Set your wake-up time, countdown duration, city, or focus intervals. Adjust sounds, display format, and font size in settings.
Use it in your browser
Everything runs in your browser tab — no download or account. Keep the tab open for alarms and timers to ring on time.
Frequently asked questions
- Is onetimer free to use?
- Yes. All onetimer tools — alarm clock, timer, stopwatch, world clock, Pomodoro, and fitness timers — are free with no subscription or hidden fees.
- Do I need to keep the browser tab open?
- Yes, for alarms and countdown timers. The alarm or timer runs in your browser tab, so keep it open (or pinned) for it to ring at the scheduled time.
- Can I set multiple alarms?
- Yes. Open the Alarm Clock and add as many alarms as you need. Each alarm can have its own time, label, and sound.
- Are my settings saved?
- Yes. Display preferences (12/24-hour format, font style, date display) and alarm settings are saved in your browser's local storage on this device.
- Do I need an account?
- No. onetimer works entirely in your browser with no sign-up, login, or email required.
- Does onetimer work on mobile?
- Yes. onetimer is a responsive web app that works on phones and tablets. For reliable alarms, keep the tab open and disable battery-saving restrictions if prompted.