Linphone vs Sip:phone

Linphone combines VoIP voice and video calling, instant messaging, and videoconferencing in one application. It uses SIP and SIP SIMPLE to interoperate with IP-PBXs, proxies, SBCs, and other SIP systems. Calling features include HD audio and video, call forwarding, concurrent calls, recording, DTMF, and Bluetooth headset support. Its Flexisip or SaaS conferencing option supports meetings with up to 50 participants and screen sharing. Messaging features depend on setup: Flexisip supports group chats, file sharing, read receipts, reactions, voice messages, and ephemeral messages; SIP SIMPLE provides basic one-to-one messaging with third-party accounts. Security features include SIP/TLS, SRTP, SRTP-DTLS, ZRTP, end-to-end encryption for exchanged media, and post-quantum encryption using CRYSTALS-Kyber. Flexisip can be hosted on premises and connected to an existing SIP server for group messaging and videoconferencing. Linphone is open source under GNU GPLv3, with proprietary licensing available for closed-source modifications. The app is available on Android, iOS, Linux, macOS, Windows, and web, with API and self-hosted options. Its free SIP service is for individual users and has no guaranteed support; paid support and maintenance are available by contacting the company.

Sip:phone extends Sipwise Class 5 Softswitch and CPBX services to Android and iOS as a mobile extension of an existing business phone system. It is intended as a white-label client for operators using Sipwise NGCP, who can customize its appearance and publish it under their own name in the Apple and Google app stores. Subscribers are managed on Sipwise C5 through interfaces such as its web interface or REST API; users can sign in with a username and password or scan a server-generated QR code. Calling includes audio and video, hold, two simultaneous calls, three-way conferences and blind or attended transfers. The app synchronizes phone contacts with Sipwise C5 subscribers and can show presence for favorite contacts. Administrators can configure whether a desk phone or mobile app rings first, or have either ring alone. Sip:phone requires an existing Sipwise server account and is not intended to support emergency calls. The App Store download is free, but commercial use requires a Sip:Phone App license; pricing is available from Sipwise Sales.