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The Best Open-Source Alternatives to Five9

Are you looking for a free or self-hosted alternative to Five9? In 2026, avoiding expensive proprietary software subscriptions is easier than ever. The open-source community has built excellent privacy-friendly tools within the Team Communication ecosystem. Currently, there are 4 active replacements available, with FreeSWITCH being one of the most prominent selections.

Quick Comparison: Five9 vs. Open Source

Full comparison: Five9 vs. FreeSWITCH
CriteriaFive9OSS Replacements
Pricing modelPaid / Monthly Fees100% Free / Self-Hosted
Data ControlThird-party ServersFull Ownership & Privacy
CustomizabilityRestricted by VendorUnlimited (Modify Codebase)

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NOASSERTION

FreeSWITCH is a highly customizable, open-source communication platform that enables private, scalable, and secure voice, video, and messaging services, serving as an excellent alternative to proprietary solutions like Five9. By leveraging FreeSWITCH, organizations can enjoy full control and flexibility over their communication infrastructure while protecting their users' data and maintaining data sovereignty.

5,052 Stars
🍴 1,815 Forks
0 Open Issues
🏷️ NOASSERTION
NOASSERTION

Asterisk is an open-source, private-by-design communication platform that empowers users to create customized VoIP (Voice over Internet Protocol) solutions for enterprise-level telephony, eliminating reliance on proprietary cloud services like Five9. With Asterisk, organizations can maintain complete control over their communications infrastructure, ensuring data security and autonomy.

3,412 Stars
🍴 1,282 Forks
0 Open Issues
🏷️ NOASSERTION
NOASSERTION

Kamailio is an open-source SIP server that enables the creation of scalable and highly available VoIP (Voice over Internet Protocol) communication systems, serving as a secure and privacy-friendly alternative to proprietary solutions like Five9. With Kamailio, organizations can build custom communication platforms that are entirely under their control, sans the vendor lock-in and surveillance risks associated with proprietary solutions.

2,891 Stars
🍴 1,113 Forks
0 Open Issues
🏷️ NOASSERTION
NOASSERTION

OpenSIPS is a high‑performance, scalable SIP server that manages voice, video, and messaging traffic, providing robust call routing, NAT traversal, and real‑time communication features; its open‑source nature, extensive modularity, and strict privacy controls make it an ideal, privacy‑friendly alternative to proprietary platforms like Five9.

1,507 Stars
🍴 667 Forks
0 Open Issues
🏷️ NOASSERTION

Frequently Asked Questions

What is the best open source alternative to Five9?

Based on GitHub community data (including star count and fork activity), FreeSWITCH stands out as one of the most reliable open-source replacements for Five9 today.

Why should I use an open-source replacement instead of Five9?

Switching to an open-source solution ensures complete data sovereignty, protects your software environment from sudden vendor price hikes, and gives you full transparent control over your tech-stack metadata.

Top Open-Source Alternatives to Five9 in 2026