Set an Alarm in X Minutes

A free online countdown timer that rings a number of minutes or hours from right now. Pick a preset or type your own time, press Set alarm, and leave this tab open — it counts down and beeps in your browser. No download, no signup.

Keep this tab open and your device awake. For an alarm that rings reliably even over the lock screen, get AVA.

A timer from now, not a clock time

This tool sets a relative alarm: it counts down from the moment you press the button. Tell it "30 minutes" and it works out that it needs to ring at, say, 3:47 PM — you never touch the clock. That is exactly what you want for searches like "set an alarm in 30 minutes", "set a timer for 20 minutes", or "wake me up in 2 hours from now." Type any combination of hours and minutes, or tap a preset, and the box shows both the live countdown and the exact clock time it will go off, so there is no guessing.

If instead you already know the wall-clock time you want — 6:00 AM tomorrow, 7:30 for the school run — you want an exact-time alarm rather than a countdown. Use the exact-time alarm clock for that; it lets you pick the hour and minute directly and rings at that time of day.

What people use a countdown alarm for

The same relative timer covers a surprising number of everyday jobs:

Studying and focused work. A 25-, 45-, or 60-minute block is the backbone of the Pomodoro technique and most deep-work routines. Set the timer, put the phone face down, and let it pull you back to the surface when the block is done instead of glancing at the clock every few minutes.

Cooking and chores. "Set a timer for 10 minutes" for pasta, a 20-minute oven check, or a 5-minute steep — anything where you need a nudge but not a specific o'clock time.

"Wake me in X hours." Landing in a couple of hours, waiting on a delivery, or resting on the sofa and you just want to be roused later — enter the hours and it rings when the time is up.

A quick power nap. If you specifically want to lie down for 20 minutes, our dedicated power nap timer is tuned for that, with guidance on how long to nap so you wake up refreshed instead of groggy. And if you are planning tonight's sleep around wake-up time, the sleep calculator counts 90-minute cycles for you.

The browser-alarm caveat (read this before you rely on it)

A browser timer is genuinely handy, but be honest with yourself about its limits: it can only ring while this tab is open and the device is awake. If your phone locks, the screen sleeps, or you switch to another app that suspends this tab, the beep may be delayed or may never play. Mobile browsers in particular throttle background tabs aggressively to save battery. So this page is perfect at your desk with the tab visible — less so for an unattended alarm you are trusting to wake you from real sleep.

That is the exact gap the AVA app is built for. As a native Android alarm it fires reliably over the lock screen, with the screen off, even after a reboot — and instead of the same tone your brain learns to sleep through, it generates a brand-new spoken, personalized motivational wake-up every morning in a natural AI voice, tied to your goals and streak and layered over wake-up music. AVA is Android-only for now (iOS is on the way — you can follow progress at aialarm.live). It is a newer app without the decade-long track record of the big sleep-tracking names, and it is not a sleep tracker; it is an alarm and habit companion. The free tier includes 7 AI-voice wake-ups per month and then falls back to a standard tone, with Premium at $9.99/month.

FAQ

How do I set an alarm for 30 minutes from now?

Tap the "30 min" preset (or type 0 hours and 30 minutes), then press Set alarm. The box shows the countdown and the exact clock time it will ring, and it plays a loud beep through your browser when the 30 minutes are up. Keep this tab open and your volume up — no download or signup needed.

Will it ring if my screen is off or the tab is closed?

No. A browser timer can only ring while this tab is open and the device is awake. If the phone locks, the screen sleeps, or the tab closes, the beep can be delayed or never play — mobile browsers throttle background tabs to save battery. For an alarm that fires reliably over the lock screen and with the screen off, use the AVA app.

How do I set an alarm for X hours from now?

Type the number of hours into the Hours field (and any extra minutes into Minutes), then press Set alarm. For example, 2 hours and 0 minutes rings two hours from the moment you press it. You can combine hours and minutes freely, up to 24 hours.

What is the difference between a timer and an alarm?

A timer (this tool) counts down a length of time from now — "ring in 20 minutes." An alarm goes off at a fixed clock time — "ring at 7:00 AM." Use a timer when you care how long from now; use an exact-time alarm when you care what time of day.