Date & Time
Countdown Timer
Start, pause, reset, and use quick countdown presets in your browser.
Ready
The timer uses the device clock to reduce drift while this page remains open. Browsers may throttle background tabs, so do not use it for safety-critical timing.
About This Tool
Use this countdown timer when you need a simple visible clock that counts down to zero. Set hours, minutes, and seconds or choose a quick preset, then start, pause, resume, or reset the timer. It runs locally in your browser and does not require an account.
How To Use It
- Enter a duration in hours, minutes, and seconds, or choose a preset.
- Select Start to begin counting down.
- Use Pause when you need to stop temporarily, then Start to resume.
- Select Reset to return to the configured duration.
Examples
Focused work
Choose 25 minutes for a focused work or study block, then take a break when the display reaches zero.
Short task
Choose the 5-minute preset for a quick review, tidy-up, stretch, or other short activity.
Custom duration
Enter 1 hour, 15 minutes, and 30 seconds when a preset does not match the interval you need.
Useful Notes
How the countdown stays accurate
The page compares the current device time with the expected finish time instead of assuming every browser interval fires exactly on schedule. This reduces ordinary timer drift.
Background-tab behavior
Browsers can slow or suspend JavaScript in background tabs or when a device sleeps. Returning to the page recalculates the remaining time from the device clock, but notifications or alarms are not guaranteed.
Local and private
The configured duration and countdown are handled in the browser. The timer does not need to upload the duration to a service to perform the countdown.
Not for safety-critical timing
Use dedicated certified equipment for medical, laboratory, industrial, navigation, or other safety-critical timing where a delayed browser or sleeping device could create risk.
FAQ
Will the timer keep counting if I switch tabs?
The target finish time remains based on your device clock. Browsers may throttle background activity, but the displayed remaining time is recalculated when the page runs again.
Can I pause and resume it?
Yes. Pause preserves the remaining duration, and Start resumes from that remaining time.
What is the maximum duration?
You can set a countdown up to 99 hours, 59 minutes, and 59 seconds.
Does it make an alarm sound?
No. This version provides a visible countdown and time-up state without relying on autoplay audio or notification permissions.
Does the timer work after my device sleeps?
The page can recalculate elapsed time after it runs again, but a sleeping device may not update the page at the exact finish moment.
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