Siperb is a modern softphone powered by WebRTC, paired with a hosted WebRTC-to-SIP proxy that connects it to your existing PBX. Rather than replacing your phone system, Siperb bridges it: if your Asterisk or FreeSWITCH PBX isn't WebRTC-ready, Siperb's proxy handles the protocol translation, NAT traversal, and media negotiation so your team can make and receive calls from a browser, mobile app, or desktop client - no hardware, no forced migration.
The softphone client runs on Web, Windows, macOS, Linux, Android, and iOS, with call recording (audio & video), blind and attended call transfer, 3-way conferencing, and end-to-end encrypted media. On the proxy side, Siperb supports inbound and outbound SIP registration, register-less connections, mobile and web push notifications, and DTLS-to-RTP media transcoding for PBXs that don't natively support WebRTC's encrypted media format.
A free Personal tier covers the hosted proxy and softphone clients for individuals and small setups. Business (£2/domain user/month) adds message and call recording storage/sync, custom integrations, and multi-user domain management. Business Pro (£5/domain user/month) adds extended storage, call transcoding, and upcoming AI agent features. Core client and proxy code is open source (AGPL-3.0) on GitHub for teams who want to self-host.