---
title: "Online Countdown Timer — Full-Screen & Shareable · ChronOtter"
description: "From sprints to pomodoros, hit zero exactly when you intend to with ChronOtter Countdown Timer."
canonical_url: "https://chronotter.com/countdown"
meta:
  "og:description": "From sprints to pomodoros, hit zero exactly when you intend to with ChronOtter Countdown Timer."
  "og:title": "Countdown Timer — Set a duration and stay on track"
---

**00:20:00**

**Duration**

**Timer Size**

**Quick Presets**

Keyboard shortcuts:

`Space`: Start/Pause`F`: Fullscreen

Keep this tab open — the alert sound only plays while this page is open.

# **Countdown Timer — Set a duration and stay on track**

From sprints to pomodoros, hit zero exactly when you intend to.

Need scheduled alerts? Use [Alarms](https://chronotter.com/alarms). Tracking a session? Try the [Timer](https://chronotter.com/timer). Coordinating with teams? Check [World Clocks](https://chronotter.com/clocks).

Jump straight to a ready-made timer: [**5 Minute Timer**](https://chronotter.com/5-minute-timer) [**10 Minute Timer**](https://chronotter.com/10-minute-timer)

## **About & how to use**

Set a duration using the HH:MM:SS input or the ± controls for hours, minutes, and seconds. You can also tap the Quick Presets to populate common times instantly. Hit Start to begin the countdown. When the timer reaches 00:00:00, you'll hear a single completion beep and see a toast confirming it finished. Use Reset to return to the last duration. Adjust the Timer Size slider anytime to make the display easier to read.

## **Tips**

- For best reliability, keep the tab open (or install the PWA) while a timer is running.
- Use Quick Presets to set frequent durations faster.
- Slide Timer Size up on mobile for large, glanceable digits.
- Make sure your device volume and Do Not Disturb settings allow the completion beep to play.

## **FAQ**

## Sitemap

See the full [sitemap](/sitemap.md) for all pages.