The classic Pomodoro is too rigid.
Here's a version that bends to your brain.
Francesco Cirillo's Pomodoro technique (1992) forces 25 minutes of work followed by 5 minutes of break. It works for many people. On an ADHD brain, it's sometimes too short (you haven't even had time to enter focus) and sometimes too long (you can't start because you know you're committing to a full 25 minutes).
This version lets you choose between four durations: 15 minutes to unblock a stuck task, 25 minutes for a standard session, 45 minutes to drop into flow, 60 minutes for an intentional hyperfocus. The end-of-session chime is quiet so it doesn't break the concentration. The tab title shows the remaining time, which helps when you have twenty tabs open.
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15 minutes. To start a task you've been pushing back for days. The point isn't to finish, it's to begin. Fifteen minutes is short enough to disarm the startup resistance. Often, at the end of those 15 minutes, you keep going because you're in it. If you didn't keep going, fine, you'll still have done 15 minutes more than before.
25 minutes. The classic Cirillo length, still useful for an average session. Best for a familiar task that doesn't need a long warm-up. Good for writing a tricky email, going through a pile of inbox messages, doing bookkeeping exercises.
45 minutes. To drop into flow. Hallowell and Ratey describe in ADHD 2.0 the moment the brain shifts into intentional hyperfocus, with output going up sharply. That moment rarely lands before 20 minutes of uninterrupted concentration. 45 minutes leaves room to capitalize on the state once it's there.
60 minutes. For an important project where you want to invest a compact block. Careful, past 60 minutes cognitive fatigue ramps up fast, especially on an ADHD brain. Better to do two 60-minute blocks with a real break in between than to push the duration.
For tasks I've been pushing back for three days, I start a 15-minute session and tell myself I can stop at the end. Nine times out of ten, I keep going. The tenth time, I've still done 15 more minutes than before, that's a win.
For long writing sessions (an article like this one, for example), I go with 45 minutes. The 10-minute break that follows is non-negotiable, I get up, I walk, I drink a glass of water. Otherwise I'll cut into the next session and wreck the whole thing.
For boring tasks (admin, invoices), I stay on 25 minutes. Past that, my brain checks out and productivity drops below zero. Better three 25-minute blocks with breaks than one 75-minute block in tears.
The Pomodoro was developed by Francesco Cirillo in the 1990s (The Pomodoro Technique, 2006 for the book edition). The ADHD variant draws on clinical observations from Hallowell and Ratey (ADHD 2.0, Ballantine, 2021) on flow in ADHD adults, and from Hallowell (Driven to Distraction at Work, HBR Press, 2014) on the individual cognitive sweet spot. The preset durations (15, 25, 45, 60) cover that sweet spot for most ADHD brains.
What this tool is not: a treatment, a substitute for medication or therapy, or a miracle method. It's a simple timer, free, to use when it helps and to leave aside when it doesn't.