What is FreeSWITCH used for?

FreeSWITCH is an open-source software-defined telecom stack that turns commodity hardware into a telephony platform for VoIP, SIP and WebRTC applications. It is a good fit for building a self-run phone system, telecom and VoIP platforms, and connecting to SignalWire for SMS and SIP.

Is FreeSWITCH open source?

Yes. FreeSWITCH is open source under a custom licence. Its source code is on GitHub at signalwire/freeswitch and is written mainly in C.

Yes. FreeSWITCH is open source, so the software itself is free to use under the terms of its own licence.

Can I self-host FreeSWITCH?

Yes. FreeSWITCH can be self-hosted on your own server or infrastructure.

What is FreeSWITCH an alternative to?

FreeSWITCH is an open-source alternative to Twilio and Vonage API. Other open-source alternatives to Twilio include LiveKit, Fonoster and OpenWA.

Is FreeSWITCH actively maintained?

Yes. The most recent commit to FreeSWITCH was on 2 October 2026, and the latest release is v1.11.3, published on 28 August 2026. The project has 5.2k stars on GitHub.

FreeSWITCH: open-source alternative to Twilio, Vonage API

About FreeSWITCH

FreeSWITCH is a software-defined telecom stack that replaces proprietary telecom switches with software running on ordinary hardware, from a Raspberry Pi to a multi-core server. It is used to build voice and communications systems around standards such as SIP, WebRTC and VoIP.

The source code is available on GitHub and can be built for Linux, Windows, macOS and BSD, with an issue tracker and pull request workflow in the repository. Documentation, release notes and step-by-step installation tutorials from packages are published online. A mod_signalwire module included in the codebase links a FreeSWITCH instance to the SignalWire cloud platform.

SignalWire, founded by FreeSWITCH's original developers, is the primary sponsor and offers services such as SMS, SIP and programmable telecom that can extend a deployment. Teams that need commercially supported builds can contact the core team about professional services. The project is written in C.

Key features

SIP and VoIP call handling
WebRTC support
Builds for Linux, Windows, macOS and BSD
Scales from Raspberry Pi to multi-core servers
mod_signalwire cloud integration
Professional support available

Good fit for

→Building a self-run phone system
→Telecom and VoIP platforms
→Connecting to SignalWire for SMS and SIP

Built with: C
Tags: voip; telephony; sip; webrtc; signalwire; freeswitch; iot; self-hosted

FreeSWITCH: questions and answers

What is FreeSWITCH used for?: FreeSWITCH is an open-source software-defined telecom stack that turns commodity hardware into a telephony platform for VoIP, SIP and WebRTC applications. It is a good fit for building a self-run phone system, telecom and VoIP platforms, and connecting to SignalWire for SMS and SIP.
Is FreeSWITCH open source?: Yes. FreeSWITCH is open source under a custom licence. Its source code is on GitHub at signalwire/freeswitch and is written mainly in C.
Is FreeSWITCH free?: Yes. FreeSWITCH is open source, so the software itself is free to use under the terms of its own licence.
Can I self-host FreeSWITCH?: Yes. FreeSWITCH can be self-hosted on your own server or infrastructure.
What is FreeSWITCH an alternative to?: FreeSWITCH is an open-source alternative to Twilio and Vonage API. Other open-source alternatives to Twilio include LiveKit, Fonoster and OpenWA.
Is FreeSWITCH actively maintained?: Yes. The most recent commit to FreeSWITCH was on 2 October 2026, and the latest release is v1.11.3, published on 28 August 2026. The project has 5.2k stars on GitHub.