Live Heart Rate Monitor

ANT+ Bridge Required

Browsers cannot read ANT+ sticks directly. You need to run a small local bridge app that reads your USB ANT+ stick and streams HR data to this page over WebSocket.

Setup:
1. Plug in your USB ANT+ stick (Garmin USB-2, Dynastream ANTUSB-m, etc.)
2. Download and run the HR Bridge script — requires Python 3 and openant
3. Install dependencies: pip install openant websockets
4. Run: python hr-bridge.py
5. Enter the WebSocket address below and click Connect

Zone Configuration

Set each zone boundary independently. The max of one zone automatically becomes the min of the next.

Z1 Recovery

Min BPM

Max BPM

Name

Z2 Fat Burn

Min BPM

Max BPM

Name

Z3 Aerobic

Min BPM

Max BPM

Name

Z4 Threshold

Min BPM

Max BPM

Name

Z5 VO₂ Max

Min BPM

Max BPM

Name

Alert: Slow Down (bpm)

Alert: Take Break (bpm)

Zone boundaries must be in ascending order.

Compatible Devices SHOW ▾

✓ Confirmed Working

Switch

Myzone

CONFIRMED

Standard BLE HR service. Works out of the box.

TICKR / TICKR X

Wahoo

CONFIRMED

Full GATT HR service support. Works out of the box.

H10

Polar

CONFIRMED

Standard GATT HR service. Best Polar option for web use.

Fenix / Forerunner / Venu

Garmin

CONFIRMED

Enable HR Broadcast in Settings → Sensors & Accessories → Wrist Heart Rate.

HRM-Pro / HRM-Dual

Garmin

CONFIRMED

Standard BLE HR service. Works without any watch pairing.

Smartwatch HR broadcast

Most brands

CONFIRMED

Most smartwatches can broadcast HR over BLE when HR broadcast is enabled.

Chest straps (generic)

Various

CONFIRMED

Any chest strap using standard Bluetooth GATT heart rate service will work.

OH1

Polar

CONFIRMED

Works via standard HR service. Must not be connected to Garmin or Polar app simultaneously.

Verity Sense

Polar

INCONSISTENT

Behaviour varies — works in some sessions, drops connection in others. Power off any paired Garmin watch before connecting. The Polar OH1 is more reliable for Web Bluetooth use.

⚠ Works with Conditions

Apple Watch

Apple

PARTIAL

Requires a third-party HR broadcast app (e.g. HRV4Training). Does not broadcast HR natively over BLE.

Mi Band / Smart Band

Xiaomi

PARTIAL

Requires HR broadcast mode enabled via Mi Fitness app. Not available on all models.

✗ Not Compatible

Any ANT+ only device

Various

ANT+ ONLY

Browsers cannot read ANT+ directly. Use the ANT+ bridge script instead.

Fitbit devices

Fitbit / Google

NOT SUPPORTED

Fitbit uses a proprietary BLE protocol and does not expose a standard HR service.

Browser Support

✓ Chrome (desktop) ✓ Edge (desktop) ✓ Chrome (Android) ✗ Safari (any) ✗ Firefox ✗ Chrome (iOS)

Web Bluetooth requires a secure HTTPS connection and is not supported in Safari on any platform, including iPhone and iPad. Android users should use Chrome.