Skip to content
OFF-GRID MESH · NO INTERNET · ENCRYPTED

Stay connected when the grid goes down, disaster strikes, or you're far from coverage.

Helius is an encrypted messenger on a long-range radio mesh. Text, voice notes, photos and live location — with no internet, no cell service and no SIM.

Flash a boardSee supported boards →

Needs a supported board and Chrome or Edge on a computer.

App coming to Android · iOS · macOS · Windows · Linux · Web
NO INTERNETNO CELL SERVICENO SIMAES-256 ENCRYPTED ON AIRVOICE + PHOTOSFREQUENCY HOPPINGSHARE ONE BOARDOTA OVER THE MESHNO GPS NEEDEDOFFLINE MAPSWRITTEN IN RUSTNO INTERNETNO CELL SERVICENO SIMAES-256 ENCRYPTED ON AIRVOICE + PHOTOSFREQUENCY HOPPINGSHARE ONE BOARDOTA OVER THE MESHNO GPS NEEDEDOFFLINE MAPSWRITTEN IN RUST
JUST WORKS

Nothing to configure. Nothing to get wrong.

Fly across the world — Helius retunes the radio for every region on its own. Nothing to pick, nothing to break.

REGIONset automatically
US915
Frequency
927.875 MHz
Bandwidth
500 kHz
Spreading
SF10
Coding rate
4/5
TX power
22 dBm
Duty cycle
100%
WHAT IT DOES

Built for when the network isn't there.

A complete messenger on a long-range radio mesh — engineered from the radio up.

On the air

HD Audio · HD Photo

Voice notes and photos, off-grid

Not just text. Hold to record a voice note or send a photo — our own proprietary compression and a high-speed media link carry them across the mesh, clear, with no network.

In the field

Find your position without GPS

Under canopy, indoors, or when GPS is jammed: Helius works out where you are from an offline cell-tower database (Android and Linux), or from the sun, moon and stars.

On the board

CPU wakesbatchedtimers
118 → 2.5

Built to sleep

The firmware batches its timers and listens for the radio in short bursts, cutting CPU wake-ups from about 118 a second to 2.5 — so the battery goes further.

GET STARTED

Off-grid in three steps.

  1. Flash a device

    Install Helius on a T-Echo, T-Beam or Heltec V3 — or convert a Meshtastic board.

  2. Pair the app

    Connect over Bluetooth or USB with the Helius app — coming soon to every major platform.

  3. Message off-grid

    Send texts, voice notes, photos and your location — and watch the mesh on the map.

HARDWARE

Runs on radios you can buy today.

Install Helius on a supported board — or convert one you already own.

T-Echo

nRF52840
DisplayE-ink
GPSBuilt in
BatteryLiPo
Phones at onceUp to 3

T-Beam

ESP32
DisplayOptional OLED
GPSBuilt in
Battery18650 cell
Phones at once1

Heltec V3

ESP32-S3
DisplayOLED
GPSPhone's GPS
BatteryLiPo
Phones at onceUp to 4
WEB FLASHER

Flash your device in the browser.

No SDK, no command line. Plug in over USB, pick your board and install from Chrome or Edge. Coming from Meshtastic on an nRF52840? One drag-and-drop file converts it.

Open the flasher
  1. Step 1

    Pick your board

  2. Step 2

    Connect over USB

  3. Step 3

    Install

ESP32 and ESP32-S3 boards install straight from Chrome or Edge. nRF52840 boards install by drag-and-drop.
MESH MAP

See your whole mesh.

In the app, every node you've heard shows up with its position, signal and last-heard time on a map that works offline. Preview the map style here.

Preview the map
MAP PREVIEW

Build your off-grid network.

No towers, no accounts, no cloud. Your keys stay on your devices.

Flash a boardRead the docs →