How do I set a countdown timer?

Enter the hours, minutes, and seconds you want in the input fields at the top of the page, then click Start. You can also click any quick preset button — for example '5 min' — to set and start a timer instantly without typing.

What is the Pomodoro technique?

The Pomodoro Technique is a time management method developed by Francesco Cirillo in the late 1980s. You work in focused 25-minute blocks called 'Pomodoros', separated by 5-minute short breaks. After four Pomodoros you take a longer 15–30 minute break. The technique reduces mental fatigue, improves concentration, and creates a sense of urgency that helps you stay on task.

How long should a Pomodoro work session be?

The classic Pomodoro work session is 25 minutes, but you can customise the duration in the Pomodoro section. Some people prefer 45-minute or 50-minute sessions for deep work. Experiment to find what length lets you stay focused without burning out.

Can I run multiple timers at the same time?

Yes. The Multiple Timers section lets you run up to five independent countdown timers simultaneously, each with its own label, duration, and controls. This is handy when cooking several dishes at once or managing different tasks in parallel.

Will the timer continue if I switch browser tabs?

Yes. The timer stores the end timestamp rather than decrementing a counter, so it stays accurate even when the browser throttles background tabs. Switching tabs or minimising the window will not cause the timer to drift or lose time.

Does the timer make a sound when it finishes?

Yes. When the countdown reaches zero a short audible beep is generated directly in your browser using the Web Audio API — no audio files are downloaded. Make sure your device is not on silent. The display also flashes and shows a 'Time's up!' message.

What is the best timer duration for studying?

Research supports study sessions of 25–50 minutes followed by a 5–10 minute break. The Pomodoro Technique's 25-minute default is a good starting point. Longer sessions of 45–50 minutes work well for tasks that require deep concentration. Avoid studying for more than 90 minutes without a proper break.

How is a stopwatch different from a countdown timer?

A countdown timer counts down from a set duration to zero — useful when you want to limit how long something takes. A stopwatch counts up from zero — useful when you want to measure how long something takes. Both are available on this page; use the Timer / Stopwatch toggle to switch between them.

Can I use this timer on my phone?

Yes. The timer is fully responsive and works on any modern smartphone or tablet browser, including Safari on iOS and Chrome on Android. All features — presets, Pomodoro, stopwatch, and multiple timers — are available on mobile.

What happens if I accidentally close the tab while the timer is running?

The timer automatically saves its end timestamp to sessionStorage every tick. When you reopen the tab or reload the page the timer detects the saved timestamp and resumes from the correct remaining time, showing a brief 'Timer resumed' notice. This only works if you reopen the same tab in the same browser session.

Online Timer

Free countdown timer that works for any duration. Use quick presets from 30 seconds to 2 hours, switch to the built-in Pomodoro timer to track focused work sessions, or use the stopwatch to measure elapsed time with lap splits. Everything runs entirely in your browser — no installation needed.

Why use our online Online Timer?

Run a countdown timer or stopwatch directly in your browser tab. Supports hours, minutes, and seconds with audio alert — no app install or account needed for a quick timed session.

How to use Online Timer

1
Set your duration
Enter hours, minutes, and seconds in the input fields, or click any quick preset button — from 30 seconds to 2 hours — to set the timer instantly without typing.
2
Start the countdown
Click Start to begin. The large display shows remaining time and the progress bar depletes as time counts down, turning red in the final 10% to signal urgency.
3
Pause or resume at any time
Click Pause to hold the timer without losing your place. Click Resume to continue from exactly where you left off. The timer stores its end timestamp so it stays accurate even in background tabs.
4
Wait for the alert
When the countdown reaches zero an audible beep plays directly in your browser and a 'Time's up!' message appears. Click Restart to run the same duration again, or Reset to start fresh.
5
Try Pomodoro or Stopwatch mode
Scroll down to the Pomodoro section to track focused work sessions with automatic session counting. Toggle to Stopwatch mode at the top of the tool to count up from zero with centisecond precision and lap times.

The Pomodoro Technique — the science and the practice

The Pomodoro Technique was developed by Francesco Cirillo in the late 1980s while he was a university student. The name comes from the tomato-shaped kitchen timer ("pomodoro" is Italian for tomato) he used during his own study sessions. The core cycle: 25 minutes of focused work, then a 5-minute break. After four consecutive pomodoros, take a longer 15–30 minute break.

The technique draws on research in cognitive psychology. Sustained attention degrades after roughly 20–30 minutes of focused effort on a single task — the brain's prefrontal cortex, which governs executive function and sustained attention, becomes progressively less efficient. Short breaks allow restoration of attentional resources, which is why work in 25-minute blocks with rest often produces more output than working for hours straight.

The structured breaks also create natural stopping points that reduce the cognitive overhead of deciding when to pause. The Zeigarnik effect — the tendency to keep thinking about unfinished tasks — is used deliberately: ending a pomodoro mid-task (with a note about where you left off) keeps the brain engaged and reduces the effort needed to re-enter the task at the next session.

Time management techniques beyond Pomodoro

The Pomodoro Technique is one of several evidence-based time management frameworks. Understanding the alternatives helps you choose the right tool for different task types.

Time blocking allocates specific time windows in your calendar for specific types of work — rather than working from a to-do list, you schedule blocks: 9–11 AM for deep writing, 11 AM–12 PM for email, 2–4 PM for meetings. It works well for knowledge workers with significant schedule autonomy. Cal Newport advocates this approach in "Deep Work" (2016).

The Eisenhower Matrix categorizes tasks by urgency and importance into four quadrants: urgent + important (do immediately), important + not urgent (schedule), urgent + not important (delegate), not urgent + not important (eliminate). It is a prioritization tool rather than an execution framework — it helps decide what to work on, not how to work on it.

Getting Things Done (GTD, David Allen 2001) focuses on capturing all commitments in a trusted external system to reduce cognitive load from open loops — the mental overhead of tracking incomplete tasks. The capture-clarify-organize-reflect-engage cycle is comprehensive but requires significant setup and maintenance.

For managing long-duration deep work sessions, many people combine time blocking (to schedule uninterrupted work windows) with the Pomodoro Technique (to structure work within those blocks).

How the browser timer stays accurate in background tabs

Browser timers are affected by a known performance optimization: browsers throttle JavaScript in background tabs and hidden pages to reduce CPU usage. This throttling can cause setInterval() and setTimeout() callbacks to fire significantly later than scheduled when the tab is not visible — by seconds or even minutes in some cases, particularly on mobile browsers and battery-saver mode.

This tool solves the background throttling problem by storing the timer's target end time (as an absolute timestamp: Date.now() + remaining milliseconds) rather than decrementing a counter. When the timer update callback fires — even if delayed — it calculates the correct remaining time by subtracting the current time from the stored end time. This clock-based approach is immune to callback delays: if the callback fires 30 seconds late, the timer simply reads 30 seconds less remaining time and updates the display correctly.

The displayed time may briefly "jump" when you return to the tab after a long period in the background — you might see the timer skip from 3:45 to 1:15 rather than count down continuously. This is the correct behavior: the timer ran accurately, it just wasn't updating the screen display while in the background.

Frequently Asked Questions

How do I set a countdown timer?: Enter the hours, minutes, and seconds you want in the input fields at the top of the page, then click Start. You can also click any quick preset button — for example '5 min' — to set and start a timer instantly without typing.
What is the Pomodoro technique?: The Pomodoro Technique is a time management method developed by Francesco Cirillo in the late 1980s. You work in focused 25-minute blocks called 'Pomodoros', separated by 5-minute short breaks. After four Pomodoros you take a longer 15–30 minute break. The technique reduces mental fatigue, improves concentration, and creates a sense of urgency that helps you stay on task.
How long should a Pomodoro work session be?: The classic Pomodoro work session is 25 minutes, but you can customise the duration in the Pomodoro section. Some people prefer 45-minute or 50-minute sessions for deep work. Experiment to find what length lets you stay focused without burning out.
Can I run multiple timers at the same time?: Yes. The Multiple Timers section lets you run up to five independent countdown timers simultaneously, each with its own label, duration, and controls. This is handy when cooking several dishes at once or managing different tasks in parallel.
Will the timer continue if I switch browser tabs?: Yes. The timer stores the end timestamp rather than decrementing a counter, so it stays accurate even when the browser throttles background tabs. Switching tabs or minimising the window will not cause the timer to drift or lose time.
Does the timer make a sound when it finishes?: Yes. When the countdown reaches zero a short audible beep is generated directly in your browser using the Web Audio API — no audio files are downloaded. Make sure your device is not on silent. The display also flashes and shows a 'Time's up!' message.
What is the best timer duration for studying?: Research supports study sessions of 25–50 minutes followed by a 5–10 minute break. The Pomodoro Technique's 25-minute default is a good starting point. Longer sessions of 45–50 minutes work well for tasks that require deep concentration. Avoid studying for more than 90 minutes without a proper break.
How is a stopwatch different from a countdown timer?: A countdown timer counts down from a set duration to zero — useful when you want to limit how long something takes. A stopwatch counts up from zero — useful when you want to measure how long something takes. Both are available on this page; use the Timer / Stopwatch toggle to switch between them.
Can I use this timer on my phone?: Yes. The timer is fully responsive and works on any modern smartphone or tablet browser, including Safari on iOS and Chrome on Android. All features — presets, Pomodoro, stopwatch, and multiple timers — are available on mobile.
What happens if I accidentally close the tab while the timer is running?: The timer automatically saves its end timestamp to sessionStorage every tick. When you reopen the tab or reload the page the timer detects the saved timestamp and resumes from the correct remaining time, showing a brief 'Timer resumed' notice. This only works if you reopen the same tab in the same browser session.