# denntatsu — Offline Walkie Talkie App, No Internet Needed

> Turn your phone into an off-grid walkie talkie. Direct P2P push-to-talk voice with no internet, no servers, no cell signal — for motorcycle rides, hiking and airsoft. Disaster SOS is free and unlimited.

Canonical: https://denntatsu.com/en/

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# Connect, Even Offline.denntatsu

Direct peer-to-peer communication without servers. Your go-to for outdoor adventures, with free unlimited disaster SOS and safety check-ins.

Works Offline

## Your New Outdoor Companion

Stay connected with teammates in remote areas—motorcycle touring, hiking, airsoft, anywhere without signal.

### Connect Instantly via QR

Scan a QR code to join offline. No servers. Works anywhere, even with no signal.

### Push to Talk, Walkie-Talkie Style

Press and hold the PTT button to send. Supports hands-free auto send and receive.

### Voice and Text Together

Send voice and text messages in parallel. Stay connected with your team in one app.

Touring → Hiking → Airsoft →

## When Infrastructure Fails, We Relay

When cell towers go down, nearby devices relay SOS and safety info peer-to-peer, spreading help across a mesh network.

When one path breaks, another carries your message.

### Send SOS Right Now

Broadcast your GPS location and situation with one tap. Disaster SOS is free and unlimited.

This app is not a substitute for emergency services (110, 119). Message delivery and latency are not guaranteed.

### Share Status Locally

Post "I'm here," "I'm safe," or requests for help on a local shared bulletin board.

### Messages Keep Relaying

Undelivered messages stay in the network, relayed through multiple hops until they reach the recipient or expire.

This app is not a substitute for official emergency systems. Message delivery, latency, and reliability are not guaranteed and depend heavily on the actual radio environment, number of devices, and distance. Disaster SOS →

## Frequently Asked Questions

Does it really work with no cell signal? +

Yes. denntatsu connects nearby devices directly (BLE control plane + Wi-Fi voice) with no server in between, so you can talk and chat even where there's no cellular reception.

Is the disaster SOS feature paid? +

No. Disaster SOS and safety-sharing are entirely free and unlimited. Only the peacetime calling feature (30-minute session limit) is part of the paid plans.

What is it used for? +

Outdoor activities with no cell signal — motorcycle touring, hiking, airsoft — and, during a disaster when cellular infrastructure is down, sending an SOS or sharing your safety status.

Which platforms are supported? +

Android is available now — download it free on Google Play. iOS is planned for a future release.

Is message delivery guaranteed? +

No. denntatsu is not a replacement for official emergency services (110/119 in Japan) and does not guarantee delivery. Actual reach depends on radio conditions, device density, and distance.

Is it hard to connect with others? +

No. Just scan a QR code to connect offline — no server registration required.

How It Works →