Countdown timer
Set hours, minutes and seconds, or choose a preset for 1, 5, 10 or 25 minutes. Pause when you need a break, then resume from the time remaining.
Keep this page open and your device awake. Test the sound before starting; switching apps or locking the screen can prevent the reminder from playing.
Ready
Set a duration
Enter hours, minutes and seconds, or choose a preset. Select Start timer to begin. Pause holds the remaining time; Resume continues from that point.
Restart or change the duration
Reset returns to the duration you entered and unlocks the fields. After the timer finishes, Start again runs the same duration.
Check the sound before starting
Keep this page open. Switching apps, locking the screen or letting the device sleep can prevent the reminder from sounding. Select Test sound to check the volume first.
To measure elapsed time and laps, use the stopwatch.
Set a Timer and Know What Happens When It Ends
Back to toolChoose a duration rather than a clock time
This timer counts down a length of time. For a five-minute break, enter 0 hours, 5 minutes and 0 seconds, or select the 5 min preset. It does not take a target date or time such as “tomorrow at 9”.
Hours accept 0–99, and minutes and seconds each accept 0–59. Set at least 1 second. Values such as 90 minutes need to be entered as 1 hour and 30 minutes; the fields do not automatically carry excess minutes into hours. Each field accepts at most two digits.
Pause for a break or reset to the original duration
Start timer begins the countdown and locks the duration fields. Pause holds the remaining time, and Resume continues from there. The fields stay locked while paused so the current countdown is not changed by an edit.
For example, suppose you set 5 minutes and pause with 3 minutes left. Resume counts down those remaining 3 minutes. Reset returns to the original 5 minutes and unlocks the fields, so you can change the duration or start again. After the countdown finishes, Start again also uses the original 5-minute setting.
Test the sound in the browser you will use
Sound is on by default. Select Test sound before starting and check the device volume and browser permissions. Testing can play the chime even if the Sound checkbox is off; that checkbox controls the finish reminder.
If you do not want a finish sound, turn Sound off. The display still changes to Time’s up! when the timer finishes. A browser that cannot start audio shows an error message; it cannot guarantee that a reminder will be audible.
Keep the timer visible for the finish reminder
The timer uses a finish time and updates the remaining duration while the page is open. If you return after it has expired, the display shows that it finished. It does not replay a reminder missed while the page was hidden.
The finish chime only plays when sound is enabled, the page is visible, audio is available and the finish is detected within two seconds. Background tabs, app switching, screen locks, sleep and delayed browser updates can prevent it. Keep the device awake and use another reminder for anything where a missed alert could cause harm.
Changing the device’s clock during a countdown can change the time remaining. This tool measures a duration within the current browser session; it is not a scheduled alarm service.
Use full screen and keep the session open
Full screen makes the countdown easier to see when the browser supports it. Entering or leaving full screen does not reset the timer. If full screen is unavailable, continue in the current window.
The duration, countdown and sound setting are held in this page’s current session. Refreshing, closing or leaving the page clears them and starts a new session with the default 5-minute duration. There is no saved timer list or background notification service.
Sources
- MDN: Page Visibility APIExplains hidden-page state and background activity limits. The finish-sound conditions above describe this timer’s implementation.
Updated