Breathing pacer.

What this does, and what it doesn’t

It is a timer with a circle attached. The circle grows while you breathe in and shrinks while you breathe out, so you can follow the pace without counting. That is the whole mechanism, and it is most of what a breathing app does.

What it cannot do is tell you whether anything happened. A web page cannot read your Apple Watch or your Apple Health history, so there is no heart rate here, no HRV, and no score at the end. Plenty of sites will show you a number anyway. It would be made up.

The optional check-in after a session is the honest version of that: your own impression, kept in your own browser.

Picking a pace

Five seconds in and five out is six breaths a minute, the rate most of the slow-breathing research uses, and a sensible place to start. If that feels rushed, try 5.5 and 5.5, or 4 and 6. If you want the evening version, lengthen the exhale and leave the inhale alone.

Slower is not automatically better. The rate that you can hold without effort for several minutes beats the one that looks impressive for thirty seconds.

Questions

Do I need an account?

No. There is no sign-up, no email field and no account. Nothing you do here is sent to a server.

Does it measure my heart rate or HRV?

No. A browser tab has no access to Apple Health or to your Apple Watch, so this pacer shows no heart rate, no HRV and no score. It paces your breathing and times the session. Anything else would be invented.

Can I change the timing?

Yes. Inhale runs from 3 to 6 seconds and exhale from 4 to 8, and the page shows the resulting rate in breaths a minute. There are no breath holds in this pacer.

What happens if I switch tabs or lock the screen?

The session clock is real time, so it keeps counting and ends when it should. The animation and the tone may stall while the tab is in the background, because browsers throttle inactive tabs. The pacer asks to keep the screen awake where the browser supports it.