Every timer, stopwatch, clock and alarm on HugeTimer follows the same rules. This page explains them in plain words, including what a web page can’t do, so you know when you can rely on a tool and when you shouldn’t.
The clock source: your device
HugeTimer has no time server. All tools read your device’s clock, the same one that shows the time in your taskbar or status bar. Most devices set that clock automatically over the internet, so it is usually within a fraction of a second of the official time. If your device clock is wrong, the clocks on HugeTimer are wrong by the same amount, while timers and stopwatches still measure durations correctly.
Timestamps instead of counted ticks
A simple web timer adds one second every time a one-second tick fires. Those ticks drift: they arrive late when the computer is busy, and browsers deliberately slow them down in background tabs. HugeTimer never counts ticks. When you press Start, it saves the moment the timer will end. Each time the screen updates, it shows the end moment minus the current time, so the display is always computed fresh. A late update can make the screen refresh a little later, but it can’t make the time wrong.
Laps and button presses use the moment of your click or key press as the browser recorded it, not the moment the page got around to handling it. That keeps lap times steady on slow devices.
Background tabs
Browsers save battery by slowing pages you are not looking at. Chrome, for example, can limit a page that has been hidden for a while to waking up about once a minute for chains of repeated timers. HugeTimer works around this in two ways. First, the moment a timer must ring is set as one direct wake-up call at the exact deadline, not as a chain of small steps. Second, the alarm sound is scheduled ahead of time on the audio clock of your device, which keeps running while the page is throttled. When you come back to the tab, everything is recalculated from the saved timestamps.
Sleep, closed lids and frozen tabs
A sleeping computer runs no web pages, so nothing can ring while it sleeps. When it wakes, the page checks the time at once. If a timer ended 60 seconds ago or less, it rings late. If it ended longer ago, it stays silent and shows how long ago it ended, for example “Time’s up — 12:04 ago”. You never get a burst of old beeps.
Clock changes and daylight saving time
Timers, stopwatches and workout timers measure durations. If someone sets the device clock back while one runs, the display does not jump backward. Clocks, alarms and date countdowns follow the clock on the wall by design, so they move with daylight saving changes and time-zone changes, as a wall clock would.
Keeping the screen awake
While a tool runs or is fullscreen, HugeTimer asks the browser to keep the screen on with the Screen Wake Lock API. According to MDN’s compatibility data (checked November 6, 2026), it works in Chrome and Edge 84 and later, Firefox 126 and later, and Safari 16.4 and later. On iPhone and iPad, apps added to the Home Screen can keep the screen on only from iOS and iPadOS 18.4. Battery saver modes can still refuse the request; each tool’s settings show whether the screen will stay on. HugeTimer doesn’t play hidden videos or silent sounds to keep a device awake.
Sound
Sounds are generated in your browser. Browsers block sound until you click or press a key on the page, so a timer restored after a reload shows the note “Sound is off — click anywhere to turn it on” until you do. Phones in silent mode and locked screens may still mute a page.
What a web page can’t do
- Ring when the browser is closed or the computer is asleep.
- Wake a locked phone the way a built-in alarm app does.
- Be more correct than your device clock.
For anything important, use your device’s own alarm as a backup.
How we test
Every timing rule above is covered by automated tests that run on simulated clocks: hidden tabs, sleep gaps, clock changes and long runs that would take hours in real time. Before each release, the tools are also checked in real browsers. When we publish measured results from real devices, they will appear on this page with their date.