Online Alarm Clock

An alarm clock in a browser tab sounds almost too simple, and that simplicity is the feature: no app to install, no account, no notification permissions to grant. Type a time — or arrive from one of the preset pages with the time already filled in — press Set alarm, and a live countdown shows exactly how long remains until the moment, automatically choosing today if the time is still ahead or tomorrow if it has already passed.

When the countdown hits zero the tab does everything short of shaking the desk: a melody generated live by the Web Audio API plays on a loop, a full-screen notice takes over the page, and the tab title starts blinking so the alarm is visible even from another window. If you do not react, the melody returns every 30 seconds until Stop is pressed — a persistent wake-up call, not a single polite chirp.

Honesty matters more in an alarm than in any other tool, so here are the real rules: the alarm works only while the tab stays open on a computer that is not asleep. Browsers may slow down timers in background tabs, so for to-the-second precision keep the tab active or visible. Sound requires one interaction with the page — pressing Set alarm counts, which is why the melody is never silently blocked. During the countdown the remaining time is mirrored into the tab title, so a glance at the tab strip is enough.

Everything happens locally: no server stores your wake-up time and nothing is tracked. For interval work rather than a fixed hour, the countdown timer is the better fit, and for structured focus sessions there is the pomodoro timer — this page is for the plain, honest job of ringing loudly at the time you chose.