Online Alarm Clock

Type the time you want, in either 12-hour or 24-hour form, and the page figures out on its own whether you mean today or tomorrow — a time that has already passed today gets read as tomorrow. Give the alarm a label, and it shows up on the page and in the tab title, so a pinned tab tells you what it is for without you having to open it.

The time you set is saved in your browser, so the page reopens right on it — reloading does not wipe out an alarm you set an hour ago. Nothing gets uploaded, there is no account, and no email address is ever asked for. The ring time itself is checked against your device clock whenever the page gets to run, instead of being ticked down — though a tab that has been throttled or frozen in the background can still delay the sound until you switch back to it.

This is the part most sites leave out. An alarm running in a browser tab needs that tab to exist — close it, quit the browser, or restart the machine, and the alarm will not sound at all. A background tab can also be delayed or frozen even while it stays open, so being open is not a guarantee either.

The device also has to stay awake. A laptop that goes to sleep or a phone that locks stops running the page entirely, so the alarm either arrives late once the device wakes up, or not at all. No browser tab can wake a sleeping device — that's the operating system's job. An installed Tauvio app has the same limit: installing it gives you a cleaner display and offline access, not operating-system alarm privileges. If you actually need to be woken up at an exact time, use your phone's built-in alarm app as a backup.

Sound has one more rule: browsers will not play audio on a page nobody has tapped or clicked yet. Setting the alarm counts as that first interaction, which is why there is a test-sound button — press it once, and you know the tab is cleared to make noise. A system notification can be shown too if you grant permission, but it's only created while the page is running at the alarm time; it can't wake a closed page.

The default tones are synthesized with Web Audio right in the browser rather than downloaded, so they play instantly and still work with no connection once the page has loaded. The optional environment chime is the one exception — picking it downloads a small audio file, and falls back to a synthesized tone if that file cannot load.

When it rings, you can stop it or snooze it, and your label stays on screen so it's obvious which alarm went off. Presets cover the times people set most often, and you can switch the clock to 24-hour — sometimes called military time — when you're setting it against a work schedule or a payroll cutoff rather than a casual wake-up time. An alarm is the right tool when you're aiming at a specific clock time; for a fixed stretch of time from now, the timer is what counts that down and chimes at the end, and for a date rather than a time today, the countdown timer is the one to use.