Pomodoro timer

What this tool does

It runs the cycle of the Pomodoro Technique: a focus session (25 minutes by default), a short break (5 minutes), and after every fourth focus session a long break (15 minutes). All three lengths and the number of sessions before a long break can be changed. When a phase ends you hear a short chime, the page tells you what comes next, and if you switch it on, your computer shows a desktop notification. While the timer runs, the time left is shown in the browser tab title, so you can see it from any other tab.

Everything runs in your browser. Your settings and the running timer are kept in this browser's local storage, so a reload does not lose your place; nothing is sent anywhere.

How to use it

1. Check the lengths under Settings. The classic values are 25, 5 and 15 minutes with a long break after four sessions; many people prefer 50/10 for deep work.
2. Press Start. Pick one task and work only on that until the chime.
3. When the focus session ends, the break starts by itself (you can turn that off). The next focus session waits for you to press Start, unless you switch on Start focus sessions automatically.
4. Skip jumps to the next phase. A skipped focus session is not counted, because an interrupted pomodoro is not a finished one. Reset puts the current phase back to its full length.
5. To get a notification, switch on Desktop notification; the browser asks for permission once. Use Test sound to check the volume before you start.

Why the time stays right in a background tab

Browsers slow down timers in tabs you are not looking at. Chrome, for example, runs ordinary timers in a hidden tab at most once a second, and after five minutes hidden it can batch chained timers to once a minute. A timer that counts its own ticks therefore falls behind. This one does not count ticks: when you press Start it stores the moment the phase ends, and every time the page wakes up it compares that moment with the clock. If the tab slept through the end of a focus session, it works out when the session ended and starts the break from that moment, not from when you came back. The chime is also scheduled in advance on the computer's audio clock, which keeps running when the page's timers are throttled.

Two limits remain. The display and the tab title in a hidden tab may update only now and then, and if the computer goes to sleep nothing can play until it wakes. Keep the tab open; closing it stops the timer.

Tips for a good session

• Decide the task before you press Start. Picking it during the session eats the first minutes.
• Keep a scrap of paper for interruptions: write the thought down and return to the task, then deal with it in the break.
• Use the break as a break. Stand up, look away from the screen, drink water; scrolling a phone is not much of a rest.
• Adjust the lengths to the work. Short sessions suit reading and admin; longer ones suit writing or coding, where getting back into the problem takes time.
• Count sessions, not hours. "Six pomodoros" is an easier plan to keep than "work all afternoon".

What the research says

The technique comes from Francesco Cirillo, who used a tomato-shaped kitchen timer as a student in the late 1980s. It is popular, but the evidence for the exact 25/5 rhythm is thin. A 2023 study at a Dutch university found that students who took scheduled breaks reported less fatigue and more concentration than students who chose their own breaks, with similar amounts of work done; a 2025 study found no overall difference between scheduled and self-chosen breaks. The fixed timer mainly helps by removing the decision of when to stop. The article on the Pomodoro technique has the details.