Free Online Timer

Our general purpose timer has no pre-set time, no assumed use case, no configuration required.  It starts at zero and does what you need it to do.  Count down from any time, count up to any time, run through zero into negative time, or loop continuously.  Tap the space bar to start timing.

Built on a precision timing engine that measures elapsed time rather than interval loops, the timer stays true under real-world conditions of browser load, tab switching, pausing and resuming.

What This Timer Can Do

Most timers are built for one direction and one use case.  This one handles all of them:

• Count down from any time — Set the start time to any value up to 99 hours and the stop time to zero.  The timer counts down and sounds the alarm when it arrives.
• Count up from zero — Set the start time lower than the stop time and the timer counts up.  Set an alarm at a specific elapsed time, or enter 99h as the stop time to run open-ended for up to 99 hours.
• Count through zero into negative time — Set the stop time to a negative value like -5:00 and the timer counts past zero and keeps going.  Shows how far over a meeting, lecture, or session has run.
• Count from negative to positive — Set a negative start time like -1:00 and a positive stop time like 30:00 to give a minute of setup time before a timed event begins.  The timer counts up through zero and into the event window.
• Loop continuously — Enable Loop and the timer resets and starts again when it reaches the stop time.  Good when you need repeating intervals, recurring reminders, or workflows built around a fixed cycle.
• Swap count direction — Click the swap button between the start and stop time fields to switch the values.  One click turns a countdown into a count-up period.

Setting the Time

The time input is forgiving so you can enter time in whatever format feels right and the timer figures it out:

• 1:30:00 or 1.30.0 or 1 30 0 — one hour and thirty minutes
• 1h 30m or 90m or 5400 — all mean the same thing
• 45s or 45 — forty-five seconds
• -5:00 — negative five minutes for pre-event setup

Enter the value, click Set, and the timer resets to your new start and stop time.  No time format rules to memorize.

Controls and Shortcuts

• Space bar — Starts and stops the timer by default.  Tap once to start, tap again to pause, tap again to resume.  No need to fiddle with the mouse.
• Reset — Stops the timer and returns to the start time.  With Auto Restart on, Reset also starts the counting.
• Keyboard shortcuts — Reassign Start, Stop, and Reset to any keys you prefer via Advanced Settings.
• Fit Width / Fit Height — Scales the time display to fill the browser window, and by default these are both on.  Combine with full-screen mode (F11) for a display readable from across the room.
• Click the title — Scrolls the page so the timer aligns with the available screen space.
• Save and share — Click the icon to copy a URL with your current settings embedded.  Anyone who opens that link loads your timer as you set it up.

I built the first version of these timers twenty years ago.  People kept using them, so I rebuilt them properly.  Users can finally link to their own alarm sound, which was the number one request all these years. There's no marketing budget here, so word of mouth helps people learn about them.  If this timer has earned a spot in your daily routine, mention it to someone who'd use it. https://timer123.com — John Whitney

Timer — Common Questions

Does this timer work on phones and tablets?

Yes.  The timer works on any modern browser across desktop, mobile, and tablet.  The display scales to fit your screen size.

Will the alarm sound if I switch to another tab?

Yes.  Whether you minimize the browser window or place the timer on another tab, alarms should sound.

How do I enter a time quickly?

Click the start time field and type in any format that feels right like 25m, 1:30:00, 90 (seconds), or 1h 15m 30s all work.  Click Set and the timer resets to your new start time.  No rigid format required.

Can I run the timer for several hours?

Yes.  Enter 99h as the stop time to run the timer for up to 99 hours.  The timing engine measures elapsed time so the total time holds true over long sessions.

Does pausing the timer lose time?

No.  Pausing preserves the time remaining or elapsed.  Press Start again and the timer resumes from where it stopped.

Can I use this as both a countdown and a count-up timer?

Yes.  Set the start time higher than the stop time to count down;set it lower to count up.  Use the swap button between the time fields to reverse direction without retyping.  If you primarily count down, the Countdown Timer is pre-configured for that.  If you primarily count up, the Count Up Timer defaults to an elapsed time display.

Timer Tips & Tricks

Timer Help