Deep Work Timer
Deep work is the stretch where the hard thing actually moves: the architecture decision, the proof, the chapter. Cal Newport gave it a name, but every programmer already knows the shape — it takes twenty minutes to load the problem into your head, and one Slack ping to drop it.
That's why this timer defaults to 90/15 instead of the classic 25/5. Ninety minutes matches the ultradian rhythm your alertness runs on, and it's long enough that the context-loading cost gets paid back with interest. The 15-minute break after is recovery, not a reward — take it away from the screen.
Treat the block as a contract: one task, phone in another room, notifications off. Most people get two or three honest 90-minute blocks a day. That's not a limitation to fix — two real blocks beat eight interrupted ones.
The timer above runs right here with real start, pause, and reset. When you want the full setup — original focus music produced in-house, an ambient mixer, and stats that only count measured minutes — the app is one click away and free to try.
Questions
Why 90 minutes and not 25?
25/5 is great for small, nameable tasks. Deep work has a ramp-up cost — often 15–20 minutes before you're really in — so a 25-minute block ends right as the ramp pays off. 90 minutes pays the ramp once and spends the rest working.
Is this deep work timer free?
Yes. It runs in your browser with no account and no ads. The Flow app has a free tier too; the paid plan adds the full music library and extra ambient sounds.
Can I change the block length?
On this page the preset is fixed at 90/15, but there are other splits — 25/5, 45/15, 50/10, 60/10 — each on its own page, and the full app lets you set custom lengths.
Does music help deep work?
It depends on the person and the music. What we can say honestly: Flow's tracks are produced in-house specifically for long focus blocks — no lyrics fighting for your attention, no jarring transitions, not a stock playlist.
Other splits
The full setup is one click away
This page is the timer on its own. The app adds original focus music — produced in-house, not stock loops — an ambient mixer, tasks, and honest stats. Free tier, no sign-up to try.