A free fullscreen timer with a big, clean countdown display. Set your duration, press Fullscreen, and the digits fill the entire screen — no navigation, no page content, no browser chrome, no ads. Press Esc to come back. It is the simplest way to turn any screen into a dedicated countdown display.
The countdown scales to the size of your display, so on a projector, classroom smartboard, or large monitor the digits are legible from the back of a room. The readout uses JetBrains Mono with tabular figures, so every digit occupies the same width — the numbers stay perfectly aligned instead of shifting sideways each second, which is distracting at large sizes and unreadable at a distance.
In dark mode the fullscreen view becomes warm off-white digits on near-black, which is easier on the eyes in a dimmed lecture hall and draws far less attention than a bright white screen.
Fullscreen takes over a whole display; Picture-in-Picture floats a small countdown on top of everything else. Use fullscreen when the screen's only job is showing the time — a projector, a smartboard, a spare monitor. Use Picture-in-Picture when you need to keep working: it stays visible over your editor, slides, or video call, and survives switching apps entirely.
| Fullscreen | Picture-in-Picture | |
|---|---|---|
| Size | Fills the display | Small floating window |
| Stays on top of other apps | No | Yes |
| Best for | Projectors, classrooms, spare screens | Working while you watch the clock |
| Exit | Esc | Close the floating window |
Polytimer keeps time in a background Web Worker instead of relying on the page's animation frames, so the countdown stays accurate when the tab is inactive, the window is minimised, or the screen is off — and the alarm still fires at zero. A service worker caches the whole app, so the fullscreen timer also works with no internet connection, which matters in classrooms and venues with unreliable Wi-Fi.
Set your duration, then press the Fullscreen button above the timer. The countdown fills the display and the navigation, tabs, page content, and browser chrome are hidden. Press Esc to return — the timer keeps running as you switch in and out.
Yes. The countdown scales to the display, so on a projector, smartboard, or large monitor the digits read clearly from the back of a room. Tabular monospace figures keep the numbers aligned instead of jumping each second — which matters a lot at that size.
Yes — drag the browser window to the second display and press Fullscreen. If you would rather not give up a whole screen, use Picture-in-Picture: a small always-on-top countdown that stays visible over every other application.
All four. Countdown, stopwatch, Pomodoro, and the multi-timer grid each have a Fullscreen button. In multi-timer fullscreen every running timer is shown at once in a large grid.
Yes. Time is kept in a background Web Worker rather than the page's animation frames, so the countdown stays accurate with the tab inactive, the window minimised, or the screen off — and the alarm still sounds at zero.
Yes — it hides the address bar and toolbars, which is the easiest way to turn a phone or old tablet into a dedicated desk timer. Adding Polytimer to your home screen gives an app-style launch with no browser UI at all.