9 Open Source Free SIP and Softphone clients

9 Open Source Free SIP and Softphone clients
Photo by freestocks / Unsplash

SIP client apps enables the user to make internet telephony calls without extensive setup. Many companies have SIP server and VoIP infrastructure ready for employees and customers.

SIP client are also called soft-phone, as it looks similar to basic phones with similar functionalities.

In this post, we list the best open source and free SIP/ VoIP clients to use without fear of being tracked.

Blink (src. Blink)

Blink is an open-source real-time communications client using the SIP protocol. I

Blink highlights

  • Easy-to -use
  • Support multiple SIP accounts
  • (macOS): iCloud account syncing between multiple computers
  • (macOS): Keychain support for encrypted password storage
  • Built-in SIP account sign-up
  • Handle TEL and SIP URLs clicked in other applications
  • Voice Over accessibility support
  • Contact management as it integrates with the operating system address book
  • Server storage (XCAP protocol)
  • Directory search (LDAP protocol)
  • Bonjour neighbours (MDNS protocol)
  • Automatic backups
  • Supports audio session for wideband and narrowband
  • Accept and reject calls
  • Chat sessions with end-to-end encryption
  • Video calls
  • File transfers

2- Linphone

Linphone is a popular softphone and VoIP client that supports HD audio and video calling.

Linphone goes beyond just making calls as it allows groups to create active meetings and group calls, exchange files, and comes with Google/ Apple built-in push notification support.

Users can get their Linphone client on almost all popular platforms as iOS, Android, macOS, Windows, and GNU/ Linux.

3- MicroSIP

MicroSIP - open source portable SIP softphone based on PJSIP stack for Windows OS.

It allows you to make high quality VoIP calls (person-to-person or on regular telephones) via open SIP protocol. From cloud of SIP providers you can choose best for you, register account and use it with MicroSIP. You'll get free person-to-person calls and cheap international calls.

MicroSIP Feature highlights

  • Small footprint (>2.5MB) and RAM usage (>5MB) - written in C and C++ with minimal possible system resources usage
  • Usability - user-friendly in daily usage
  • Functionality - voice; video H.264 and H.263+, VP8; SIMPLE messaging (RFC 3428) and presence (RFC 3903, 6665); DTMF In-band, RCF2833, SIP-INFO.
  • Compatibility - conform to SIP standards
  • Voice quality - supports best voice codecs: Opus, G.711 A-law and μ-law, G.722, G.721.1, G.723, G.729, GSM, AMR, AMR-WB, iLBC, Speex, SILK and Linear PCM mono/stereo.
  • WebRTC echo cancellation algorithm and voice activity detection
  • Privacy - configurable encryption TLS / SRTP for control and media
  • Portability - has no additional dependencies and stores setting in ini file
  • Multilanguage and RTL support, localization for bulgarian, chinese, dutch, estonian, finnish, french, german, hebrew, hungarian, italian, korean, norwegian, polish, portuguese, russian (микросип), spanish, swedish, ukrainian, ...
  • Can be used by people with visual impairments using screen reader software such as NVDA

4- Sipdroid (Android)

Sipdroid is a free open-source VoIP and SIP client for android devices. Android users can download it from Google Play, or F-droid stores.

The app routes calls dialed from your phone's built-in contacts app to VoIP. In settings you can choose when to use VoIP and when to make standard phone calls, based on being logged in to Wifi, and/or based on number prefixes. Visit sipdroid.org for more info.

For optimal battery usage reserve a free VoIP PBX on pbxes.org, and manage your SIP trunks using a web browser.

6- ctxPhone

The ctxPhone app is a simple open source JavaScript-based SIP phone client for building rich telephony web apps.

It features a simple interface, allowing users to hold, and resume multiple calls, contact list, allows users to reject calls, and search phone numbers.

7- Telephone (macOS)

Telephone (src. App Store)

Telephone is a VoIP program which allows you to make phone calls over the internet. It can be used to call regular phones via any appropriate SIP provider.

If your office or home phone works via SIP, you can use that phone number on your Mac anywhere you have a decent internet connection.

You can download the app from the macOS App Store, however it has In-App purchase for more advanced features.

8- Ekiga

Ekiga (formerly known as GnomeMeeting) is an open source SoftPhone, Video Conferencing and Instant Messenger application over the Internet.

It supports HD sound quality and video up to DVD size and quality.

Because it uses both of the major telephony standards (SIP and H.323), it is interoperable with many service providers and many types of hardware and software.

Ekiga features highlights

Main Features of the Ekiga Softphone in a nutshell Version 4.0:

  • Ease of use with a modern Graphical User Interface
  • Audio and Video free calls through the internet
  • Free Instant Messaging through the internet with Presence support
  • Audio (and video) calls to landlines and cell phones with support to the cheapest service providers
  • High Definition Sound (wideband) and Video Quality up to DVD quality (high frame rate, state of the art quality codec and frame size)
  • Free of choice of the service provider
  • SMS to cell phones if the service provider supports it (like the default provider)
  • Standard Telephony features support like Call Hold, Call Transfer, Call Forwarding, DTMF
  • Remote and Local Address Book support: Remote Address Book support with authentification using the standard LDAP technology, Local Address support in Gnome (Evolution)
  • Multi-platform: Windows and GNU/Linux
  • Wide interoperability: Ekiga use the main deployed stantards for telephony protocols (SIP and H.323) and has been tested with a wide range of softphones, hardphones, PBX and service providers.

9- Call.Center

Call.Center is a free multiplatform SIP and VoIP client for enterprise users.  It works with a SaaS system for enterprise to manage, control their incoming and outgoing calls for their employees.

The app presents a unique, simple-to-use, and intuitive drag-to-call user interface. All its necessary functions are displayed front and center, smoothly integrating and optimizing voice operations with the workflow processes.

A fully-featured management portal is provided to use in conjunction with the call.center™ apps. This allows administrators to securely configure and maintain apps installed on user devices, regardless of their location or operating system. This means that SIP passwords are hidden from users, providing a significant layer of security for the underlying network.