Download. Open. Talk. That's It.

FREEPTT works like push-to-talk radio — press to talk, release to listen. Getting started on the public network takes minutes and requires nothing more than installing the app. No email. No password. No account.

Step 1: Download and Open the App

FREEPTT runs on Android including older hardware. Minimum supported version is Android 4.4 (KitKat), API 19.

Download the APK from the official download page.
Install and open the app. On first launch, the app generates your device's cryptographic identity automatically.
The app connects to the public network. You're ready.

There is no registration step. You are identified by your device's cryptographic identity — not an email or profile.

Hardware PTT buttons are supported on many rugged devices (e.g. RT4, RT5, Crosscall Trekker, Sonim XP5700 / XP3800). On other devices, volume keys can serve as PTT.

Step 2: The Public Network — or Your Own

Public network (default)

The app connects to the FREEPTT public network out of the box — vendor-operated, redundantly hosted, free within the monthly usage allowance.

Your operator's network

If your organization runs a licensed system, your administrator provides a server address or QR code. Add it under Server Management; the app fetches and verifies the operator certificate before saving.

Multiple networks

You can use more than one network. The public network and a private system can coexist — switch with a tap. Each connection completes mutual authentication before voice flows.

Step 3: Choose Your Channel (Talkgroups)

Talkgroups are the unit of communication — like radio channels. Each has a type and encryption mode.

Group (open): Shared channel; audio unencrypted; broad coordination.
Group (encrypted): Same structure with AES-256-GCM end-to-end encryption.
Broadcast: One designated transmitter; others receive — open or encrypted.
Private / individual: Point-to-point; always encrypted with call setup.

You can monitor multiple talkgroups using scan lists, similar to conventional radio.

Step 4: Push to Talk

Press and hold the PTT control. A visual indicator confirms transmit. Release to listen.

On encrypted calls, audio is Opus-encoded, wrapped with a per-press AES-256-GCM key, and session keys are exchanged using RSA-OAEP. On open group channels, frames are authenticated but not encrypted.

Multi-System Support

Add servers from Server Management: Add Server → scan QR or enter host → verify certificate → select active system. Each system has its own trust configuration.

Device Enrollment (Private Networks)

The public network does not require enrollment. Some private operators require enrollment: your admin issues a code; you enroll in the app; your device receives an operator-issued certificate.

FAQ

Do I need an account?: No for normal use on the public network. An optional billing account may arrive later for unlimited usage beyond the free allowance.
How is my device identified?: By a Device Numeric Identity (DNI) derived from your public key — not your name or email unless you register for billing.
Which calls are encrypted?: All private calls are always E2E encrypted. Group channels may be open or encrypted depending on operator configuration.
Does FREEPTT work offline?: It requires IP connectivity to your operator's server — it is not peer-to-peer RF.

Download the App