tool / released

Nearby Signal

See the Bluetooth activity already around you.

A native macOS view of nearby Bluetooth Low Energy broadcasts, their relative signal strength, and packet cadence.

$brew tap scotthaleen/nearby-signal https://github.com/scotthaleen/nearby-signal
$brew install --cask scotthaleen/nearby-signal/nearby-signal
Nearby Signal inspector showing a live signal reading and twenty-second trend

Nearby Signal turns the Bluetooth Low Energy advertisements that macOS can already hear into a live, readable signal view. The overview is for surveying a room and narrowing a crowded scan, while a separate inspector follows one advertiser’s signal and packet behavior over time.

The app stays within the limits of the radio data it receives. Signal strength can show whether a broadcast is getting stronger or weaker, but walls, people, interference, transmit power, and device orientation prevent it from acting as a distance meter or directional finder.

Nearby Signal is available for macOS 13 or later as a Homebrew cask. Version 0.1.0 installs both the application and a nearby-signal terminal launcher; the app asks for Bluetooth permission on first launch.

The current release is ad-hoc signed rather than Developer ID signed and notarized. macOS may require approval in System Settings > Privacy & Security before the first launch.

What the interface makes visible.

01

Live signal overview

Rank active BLE advertisers by smoothed received signal strength, with packet count, sample age, and periodic resorting visible.

02

Names without guesswork

Use advertised names when devices publish them and label unidentified broadcasts as unnamed instead of inferring an identity.

03

Focused inspection

Open one signal to compare raw and smoothed RSSI, packet timing, observed receive rate, services, and advertisement metadata.

04

Honest quiet periods

Plot samples on a real time axis, hold the last measurement during radio silence, and show when the display is receiving or waiting.

05

Local by design

Listen passively through CoreBluetooth without connecting to devices, uploading observations, or saving scan history.

06

Explicit limits

Present RSSI as a relative trend, not exact distance, direction, ownership, or a public Bluetooth hardware address.

Move from the broad view to the useful detail.

  1. 01

    Install

    Use the Homebrew cask to install the macOS app and its nearby-signal terminal launcher.

  2. 02

    Survey

    Open the app and let the overview collect a room-level signal snapshot.

  3. 03

    Narrow

    Filter by advertised name, classification, source, or service identifier.

  4. 04

    Inspect

    Select one card to watch its signal trend, cadence, and current advertisement details.

The inspector separates signal trend from packet cadence so quiet radio time is not mistaken for a zero reading. The advertised device name has been anonymized.

Inspect the implementation.

The repository remains the source of truth for installation, current behavior, and development status.

View Nearby Signal on GitHub