You do not need expensive desk phones to use SIP trunking. These free softphone apps turn your computer or smartphone into a full-featured business phone that connects to your Asterisk or FreePBX system.
A softphone is a software application that acts as a SIP phone. Instead of a physical desk phone, you use your computer or mobile device with a headset. Softphones register to your Asterisk PBX just like a hardware phone would.
Desktop
Windows, Mac, Linux apps
Mobile
iOS and Android apps
WebRTC
Browser-based, no install
Free Softphone Comparison
Softphone
Platforms
TLS/SRTP
Video
Best For
Linphone
Win/Mac/Linux/iOS/Android
Yes
Yes
Cross-platform, open source
MicroSIP
Windows
Yes
No
Lightweight, minimal
Zoiper (Free)
Win/Mac/Linux/iOS/Android
Paid only
Paid
User-friendly, polished UI
3CX Web Client
Win/Mac/Linux/iOS/Android
Yes
Yes
3CX PBX integration
Grandstream Wave Lite
iOS/Android
Yes
No
Mobile-first, simple
1. Linphone (Best Overall Free Option)
Linphone is fully open-source and works on every platform. It supports TLS, SRTP, and video calling out of the box with no paid upgrades needed.
Pros
Fully free and open source
All platforms including Linux
TLS + SRTP encryption
Video calls and messaging
Multiple accounts
Cons
UI not as polished as paid apps
Can be complex to configure
Push notifications unreliable on mobile
Building this? Your PBX will need a number
Find a phone number for your trunk
Local numbers $1.50 a month, toll-free $2.00, $1.00 one-time setup. Pick one here and it carries into signup.
Enter an area code, or wait a moment for numbers near you.
MicroSIP is an ultra-lightweight Windows softphone. The installer is under 10 MB and it uses minimal system resources. Perfect for call center agents or users who just need voice calling.
Pros
Tiny footprint (< 10 MB)
Starts in seconds
TLS/SRTP support
Open source
No bloat or unnecessary features
Cons
Windows only
No video calling
Basic UI (functional but plain)
No mobile version
3. Zoiper Free (Best UI)
Zoiper has the most polished user interface of the free options. The free version supports one SIP account with basic calling. TLS/SRTP and some advanced features require the paid version.
Pros
Clean, intuitive interface
All platforms
Good audio quality
Contact integration
Easy to set up
Cons
TLS/SRTP requires paid ($50)
Only 1 account in free version
Nag screens for paid features
No video in free version
WebRTC: No Install Needed
If you do not want to install any software, WebRTC softphones run directly in your browser. IPComms offers a built-in WebRTC phone in the customer portal:
IPComms WebRTC Phone
No software to install - works in Chrome, Firefox, Edge
Encrypted by default (WSS + SRTP)
Click-to-call from the portal
Works alongside your Asterisk system
Setting Up a Softphone with Asterisk
Regardless of which softphone you choose, the configuration is similar. You need these settings from your Asterisk administrator:
Setting
Value
Notes
SIP Server
your-asterisk-ip
Or domain name
Username
101
Your extension number
Password
(from admin)
Extension secret
Transport
UDP or TLS
TLS recommended
Port
5060 or 5061
5061 for TLS
Codec
G.711 ulaw
Best quality
Stop worrying about SIP trunk capacity. We have you covered.
SIP trunking from a US carrier since 2002: $0.009 per minute inbound, $0.010 outbound, numbers from $1.50 a month, $0 per channel, no contracts.
