What the Zen Box Breathing Timer does
This timer guides you through box breathing: breathe in for four seconds, hold for four, breathe out for four and hold for four, following a dot that travels round a square. Press Start and breathe with it; you can also choose 4-7-8 breathing, slow coherent breathing at about five and a half breaths a minute, a longer out-breath, or your own timings, and set the number of rounds.
Optional soft tones and phone vibration mark each step, so you can close your eyes. The guide runs entirely in your browser: timings come from the clock rather than from counting animation frames, so it stays accurate even if your phone is slow, and if your system asks for reduced motion the dot stays still and the active side of the square lights up instead. Keep the tab open and visible while you use it.
How to use it
- Choose a pattern, or type the seconds for each of the four steps. A hold can be set to 0 to skip it.
- Set the number of rounds; one round is one full breath, and the page shows how long the session will last.
- Tick "Soft tone" or "Vibrate" if you want a cue at every step. Sound starts only after you press Start.
- Press Start. Breathe in as the dot climbs the left side (or the circle grows), hold along the top, breathe out down the right side and hold along the bottom.
- Pause at any time and resume where you left off; Reset clears the session. When it finishes, sit and breathe normally for a moment before you stand.
Reading the results
Breaths a minute tells you how slow the pattern is. Box breathing at 4-4-4-4 is 3.75 breaths a minute; 4-7-8 is about 3.2; coherent breathing at 5.5 seconds in and out is about 5.5. Ordinary resting breathing is around 12 to 20.
If a hold feels uncomfortable, shorten it - 3-3-3-3 is still box breathing. Comfort matters more than the number.
The countdown shows whole seconds left in the current step, and the bar shows how much of the session is done.
Slow breathing exercises are widely used to settle nerves and are described by health services as a simple relaxation technique. This timer is a guide, not a treatment.
Worked example: four rounds of box breathing
Pattern 4-4-4-4: each round is 4 + 4 + 4 + 4 = 16 seconds, which is 60 / 16 = 3.75 breaths a minute. Four rounds take 4 x 16 = 64 seconds, shown as 1m 4s.
At 37 seconds after Start you are in round 3 (37 / 16 = 2.3, so two full rounds are done), 5 seconds into it: the first hold, with 3 seconds left. That is worked out from the clock on every update, so if the browser pauses drawing for a moment the guide jumps to the right place instead of falling behind.
With 4-7-8 there is no second hold, so a round is 4 + 7 + 8 = 19 seconds and the guide is a circle that grows and shrinks rather than a square.
Formulas and scoring rules
- Round length
cycle = in + hold + out + hold (seconds); session = cycle x rounds- Breaths per minute
60 / cycle- Where you are
elapsed = now - start - paused time; round = floor(elapsed / cycle) + 1; step = the phase containing elapsed mod cycleRecomputed from Date.now() on every frame and on a timer that keeps running when animation frames stop.
Limitations: what the result does not prove
- Browsers slow down timers in background tabs and may sleep the screen. The page keeps the screen awake while a session runs where the browser allows it, but switching away can delay sounds and vibrations until you come back; the position always catches up correctly.
- Vibration works only on devices and browsers that support it, which excludes iPhones.
- If you feel dizzy, light-headed or short of breath, stop and breathe normally. People with heart or lung conditions, or who are pregnant, should keep holds short and follow their doctor's advice.
- This is a breathing guide, not medical treatment for anxiety, panic or any other condition.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- NHS - Breathing exercises for stress
- W3C - Animation from interactions (prefers-reduced-motion), WCAG 2.2
- MDN - Screen Wake Lock API
Frequently asked questions
How do you do box breathing?
Breathe in through your nose for a count of four, hold for four, breathe out slowly for four, then hold with empty lungs for four, and repeat. Press Start here and follow the dot round the square, one side per step.
How long should a box breathing session last?
Many people use it for one to five minutes - four rounds take just over a minute. Start short; if you feel comfortable, add rounds. There is no benefit in pushing through dizziness.
What is the 4-7-8 breathing technique?
Breathe in for four seconds, hold for seven and breathe out for eight, with no hold afterwards. It is slower than box breathing, about 3.2 breaths a minute. Choose it from the pattern list; the guide becomes a circle.
Can box breathing help with anxiety?
Slow, paced breathing is commonly recommended as a simple way to feel calmer, and health services such as the NHS describe breathing exercises for stress. It is a self-help technique, not a replacement for care if anxiety is affecting your life.
Does the timer work with sound off or without looking?
Yes. Tick the soft tone to hear a cue at each step, or vibration on Android phones. Tones play only after you press Start, because browsers block sound that a page starts on its own.
Why does the dot not move on my device?
Your system is set to reduce motion, and the page respects that: the active side of the square lights up and the countdown changes each second instead. You can change the setting in your device's accessibility options if you want the moving guide.
Last reviewed by the A2Z.Tools team against the sources listed above.
