FreePBX is a popular open‑source PBX built on Asterisk, but many organisations look for other free VoIP platforms that offer different feature sets, architectures, or community support. Below is a curated list of the 20 most widely‑used free / open‑source VoIP solutions that can serve as alternatives to FreePBX.
Get targeted exposure with custom position pinning and highlighted placement.
The original open‑source telephony engine that powers many PBX solutions; highly modular with a massive ecosystem of add‑ons.
Scalable, multi‑protocol softswitch designed for voice, video, and chat; often used as the core for other PBX projects.
Web‑based GUI for FreeSWITCH offering multi‑tenant PBX features, call routing, and voicemail.
Community‑driven fork of Elastix; integrates Asterisk with CRM, call‑center, and reporting tools.
Open‑source unified communications platform built on Asterisk, providing web UI, APIs, and multi‑tenant support.
High‑performance SIP server ideal for large‑scale deployments, load balancing, and routing.
Feature‑rich SIP proxy/server offering advanced routing, NAT traversal, and carrier‑grade reliability.
Windows‑based PBX with a free tier for up to 8 simultaneous calls; includes web conferencing and mobile apps.
Legacy all‑in‑one communications suite (PBX, email, fax, IM) built on Asterisk; still used in many legacy environments.
Open‑source call‑center solution that adds predictive dialing, inbound/outbound routing, and agent management on top of Asterisk.
User‑friendly web UI for ViciDial, simplifying installation, monitoring, and reporting for call centers.
Modular telephony engine supporting VoIP, PSTN, and SMS; can be used as a PBX or SIP router.
Enterprise‑grade SIP communications platform offering PBX, voicemail, and video conferencing; now part of the 2600Hz project.
Community‑driven SIP server providing core telephony services, often paired with other PBX front‑ends.
Formerly a popular Asterisk‑based distribution with a web GUI; still maintained by community forks.
Pre‑configured Asterisk distribution with a web interface; offers a quick start for small‑to‑medium deployments.
Open‑source billing and rate‑engine that can turn an Asterisk server into a full‑featured VoIP carrier.
Lightweight Asterisk‑based PBX with a simple web UI, targeting small businesses and hobbyists.
Free community version of Mitel’s SIP PBX, offering call routing, voicemail, and basic call‑center features.
Open‑source analytics engine for Asterisk and FreePBX; often used alongside other PBX platforms to provide detailed call‑center reporting.