FreeSWITCH vs Infobip Voice API

FreeSWITCH is an open-source framework for real-time voice and video communications. It can route calls, bridge video, transcode media, and connect protocols, and is designed for use in carriers, contact centers, and communication products. Its Event Socket exposes call control, channel management, and internal events to external processes over TCP. Integrations include HTTP backends, embedded Lua, Perl, Python, JavaScript, Java, and SignalWire connectivity. The mod_signalwire module connects to SignalWire for inbound and outbound PSTN calling over a persistent WebSocket session. Linux installation guidance covers Debian and Ubuntu using SignalWire packages or a source build. A free SignalWire account is required to access packages and downloads. FreeSWITCH is licensed under MPL 2.0 and can run in production at no cost; self-hosting requires dedicated resources to maintain on-premises infrastructure. The open-source edition has community support, while FreeSWITCH Pro offers commercial support, hardened builds, priority patches, and commercial modules including answering machine detection and licensed G.729 Annex A encoding and decoding.

Infobip Voice API provides programmable voice tools for mobile and web applications, including calls to landlines and mobile phones. Developers can use Calls API to build inbound and outbound applications and control calls over PSTN, WebRTC, or SIP. Available functions include programmable calls, voice messages, IVR with DTMF collection, click-to-call, number masking, and browser-based WebRTC. SIP trunking connects a PBX or SBC to Infobip, with static and dynamic inbound call-routing rules. Voice can also be used with Infobip Inbox, Customer Profiles, Chatbots, and Journeys, and calling is documented for WhatsApp and Viber. Speech tools support text-to-speech in more than 100 languages and accents, as well as speech capture and transcription. Native SDKs are supported for JavaScript, Android, and iOS. The service has no free plan, but offers a 60-day trial with limits: 15 outgoing calls or voice messages, 15 incoming calls, and 100 WebRTC calls. Trial phone calls require verified mobile numbers and are capped at five minutes. Recording and conferencing are add-ons; conferencing is required for calls with three or more participants.