How Pulse works

Pulse — Send Your Heartbeat

Pulse records six seconds of a real heartbeat on Apple Watch and sends it in Messages. The person receiving it doesn't just read that you're thinking of them — they feel your heart beating in their hand.

Sending a heartbeat

1. Record on your Apple Watch Open Pulse on the watch and tap Record. It waits until the sensor has a steady reading, then captures six seconds. Keep your wrist still while it counts down.
2. Find it on your iPhone The recording travels to your iPhone on its own and appears under Latest. Tap its name to call it something — "Dad", "the morning we left" — or leave it untitled.
3. Feel it yourself first Play taps it out once. Loop repeats it steadily. The line across the tile is the actual rhythm that was recorded, and it lights up beat by beat as it plays.
4. Send it in Messages Tap Send, or open a conversation and choose Pulse from the + menu. Pick the recording and send it like any other message.
5. They tap once and feel it The heartbeat arrives as a card in the conversation. Tapping it plays the rhythm through their iPhone, and it's saved to their Pulse app so they can return to it.

Why it feels like a heartbeat

Every beat is shaped like a real one — the deep lub, the lighter dub, and the pause between them. The spacing comes from your own recording, so a rhythm that wandered while you breathed still wanders when it plays back.

Pulse also reads your heart rate variability, a measure of how irregular your heart is that differs from person to person. It means two people recorded at the same pulse don't feel the same. A fast heart hits harder than a resting one, the way it does in life.

Playback strength on the home screen sets how firmly heartbeats play on your iPhone. It starts at 90%.

Resting with one

Loop a recording and Pulse fades to a near-black screen after thirty seconds while it keeps playing, so you can hold it in the dark without the display in your eyes. The name of the recording stays on screen. Double-tap to bring the display back. It's worth plugging in first — a long loop is easier on a charger.

Keeping them

The newest heartbeats sit on the home screen. Everything else lives under Past recordings, along with where your library is stored.

• Recordings stay on your iPhone and are included in your encrypted iPhone backup.
• Keep a copy in iCloud, under Past recordings → Storage, keeps a copy in your own private iCloud so a lost or replaced phone doesn't take them with it.
• Deleting asks first. Anything removed goes to Recently Deleted and can be restored for 30 days — some heartbeats can never be recorded again.

From an EKG printout

If you have a paper EKG strip — the kind hospitals often send families home with — Pulse can read the beats from a photograph of it and play that rhythm back. It works without an Apple Watch, and for a heart that has already stopped.

On the home screen, tap From an EKG printout. Lay the sheet flat in even light, turn the phone sideways, and fill the frame with the printed grid — the whole sheet, with as little of the white margin as you can. Pulse finds the page, splits it into its rows and reads the clearest one, so a close-up of a single strip works less well, not better. The small printed squares need to stay visible, because Pulse measures them to work out the timing.

There is a sample strip built into the app if you want to see how this works before going to find one of your own — it is on the same screen, under Try a sample strip.

Before anything is kept, Pulse shows your photo with a mark on every beat it found. Check the marks land on the tall spikes. If they don't, take it again with more of the sheet in frame. If the strip was printed at 50 mm/s rather than the usual 25, switch the paper speed and it will re-read it.

If Pulse can't read a photo it says which part it couldn't manage rather than just failing — whether it couldn't find the printed grid, couldn't follow a line across it, or found some beats but too few to be sure of them. Each one tells you what to change. Pulse would rather refuse than guess a rhythm that wasn't there.

Pulse reads when the heart beat and nothing else. It doesn't reconstruct the waveform, doesn't interpret the trace, and is not a medical tool. The photo is analysed on your iPhone and never leaves it.

Recording someone else

On the watch, choose Someone Else before you record, and put the watch on their wrist. Heart rate variability stored on a watch belongs to its owner, so for another person Pulse uses a value from the healthy population range instead — rather than quietly shaping their heartbeat with your data.

What you need

• To record: an Apple Watch on watchOS 10 or later, paired to an iPhone on iOS 17 or later. The heart rate sensor is on the watch, so recording isn't possible without one.
• To receive and feel a heartbeat: just an iPhone.

Heartbeats are felt through the iPhone's Taptic Engine, which is why Pulse is an iPhone app — iPad has no equivalent hardware.

If something isn't working

The watch app didn't install

Open the Watch app on your iPhone, scroll to Available Apps, and tap Install next to Pulse.

The watch can't find a heartbeat

Tighten the band — a loose watch is the usual cause. Keep your wrist still, turn off Low Power Mode, and check that heart rate access is allowed under Settings → Privacy & Security → Health → Pulse.

Pulse asks permission to save workouts but never saves one. Reading live heart rate on watchOS requires an active workout session, and that permission only exists to open the sensor.

I can't feel the playback

Raise Playback strength, confirm system haptics are on under Settings → Sounds & Haptics, and hold the phone loosely in your palm rather than gripping it or leaving it on a table.

Getting in touch

Privacy

Pulse has no account, no server, and no analytics, and nothing is ever sent to the developer. The privacy policy explains what's stored and where.