Linphone

Overview

Linphone brings calling, instant messaging and videoconferencing into one application, built to work with IP-PBXs, proxies, SBCs and other SIP systems. That makes it a sensible fit where a compatible phone service is already in place; it is less compelling for anyone expecting a standalone app to provide the same feature set regardless of service.

The app is open source under GNU GPLv3 for integration into projects. Closed-source modifications require a proprietary license, an important distinction for companies planning a branded or commercially customized product.

Key features

Calling and conferences

HD audio and video, call forwarding, concurrent call management, recording, DTMF and Bluetooth headset support cover common calling needs, from routine conversations to managing multiple calls. Flexisip or the SaaS conferencing option adds video meetings for up to 50 participants and screen sharing, making Linphone more useful to teams than a basic dialer.

Messaging depends on the service

With Flexisip, Linphone supports one-to-one and group chats, file sharing, read receipts, reactions, voice messages and ephemeral messages. SIP SIMPLE with third-party accounts provides only basic one-to-one messaging, so users who need the fuller chat experience must plan around Flexisip rather than assume it comes with any SIP account.

Integration and security

LDAP and CardDAV contact synchronization, OpenID Connect and OAuth 2.0 authentication, and Apple APNs and Google Firebase push notifications help connect the app to existing identity, contact and notification systems. Its security options include SIP/TLS, SRTP, SRTP-DTLS, ZRTP, end-to-end encryption for exchanged media, and post-quantum encryption using CRYSTALS-Kyber. These capabilities suit deployments with specific security requirements, while the choice of protocols and service setup still matters.

Self-hosting and customization

Flexisip can be deployed on premises and connected to an existing SIP server for group messaging and videoconferencing. Belledonne Communications also offers white-label branding, support contracts, development assistance and custom feature development. Those options give organizations room to shape a deployment, but proprietary customization and paid services require contacting the company.

Pricing

The free plan is a strong starting point for individual SIP users who can manage without guaranteed support. Free SIP service is reserved for individuals; organizations needing support or maintenance can contact the company about paid services. White-label work and custom development also use custom pricing. Closed-source modifications require a proprietary license, so the free app alone is not a route to a closed-source customized product.

Platforms

Linphone is available for Android, iOS, Linux, macOS and Windows, as well as web, API and self-hosted deployments. It offers mobile and desktop apps, but not browser calling; the web and API options should not be mistaken for in-browser calls.

Who it's for

Choose Linphone if you need a no-cost SIP client across mobile and desktop, value interoperability with existing SIP infrastructure, or want an open-source base for a customized or self-hosted communications setup. It is a weaker fit if you expect guaranteed support with the free SIP service or need advanced messaging without deploying or using Flexisip.

Pros and cons

Pros

• Broad SIP interoperability: designed to work with IP-PBXs, proxies, SBCs and other SIP systems, which helps it fit into existing telephony environments.
• Wide calling feature set: recording, forwarding and concurrent call management sit alongside HD audio and video.
• Deployment flexibility: open-source integration and on-premises Flexisip support give organizations options beyond a standard client setup.
• Free individual service: individual users can use the app and SIP service without paying.

Cons

• Messaging varies by setup: full group chat and related features require Flexisip; third-party SIP SIMPLE accounts provide basic one-to-one messaging.
• No guaranteed free-service support: individuals relying on free SIP service should be prepared to manage without guaranteed assistance.
• No browser calling: users looking for calls directly in a browser should choose another option.
• Closed-source customization requires licensing: GPLv3 integration does not cover proprietary modifications.

Alternatives

For a broader shortlist, see Softphone Software.

• Blink is another free-plan option; its free desktop downloads for Linux, Mac and Windows require a SIP account.
• Siperb Mobile Softphone offers a free Personal plan with limited storage, seven-day SIP trace and registration activity logs, community support and no technical support.
• SipPulse Softphone offers a free App SipPulse plan for iOS, Android, Windows and Linux, with unlimited users and installations.
• Zoiper may suit non-commercial users who want a free softphone capped at one account and two lines.
• MicroSIP is a free Windows desktop SIP softphone under GPL v2, a narrower choice for Windows-only use.
• Browser Phone is a free, open-source project for web and self-hosted use.
• SessionTalk Softphone may suit teams seeking a paid plan with five seats included for 20.00 USD per month, plus 3 USD per extra seat.
• Softphone.Pro is another option with a free trial and selectable monthly or annual billing for subscriptions of 1, 6 or 12 months.

Verdict

Linphone is a strong choice for individual SIP users and organizations that value interoperability, open-source integration or self-hosted messaging and conferencing. Its combination of free access and broad calling features is the main reason to choose it. Look elsewhere if you need browser-based calling, guaranteed support with a free account, or full messaging features without a Flexisip setup.