What MicroSIP does

MicroSIP is an open-source SIP softphone for Windows, released under GNU GPL v2, providing voice, video, instant messaging, and presence for desktop business communication. The application is built on the PJSIP stack with WebRTC-based echo cancellation and supports a broad codec set (Opus, G.711, G.722, G.729, H.264, VP8/VP9) plus TLS, SRTP, and DTLS-SRTP encryption. It is designed for standards-based interoperability with SIP providers and PBX systems including Asterisk, FreePBX, and 3CX, and ships in a full version and a Lite variant (no video, lower memory footprint) in installer and portable formats.

The product targets office PBX users, SIP service provider customers, remote/hybrid workers, support desks, and small business VoIP deployments. MicroSIP monetizes through a Custom Build service (branded EXE/MSI installers with digital signatures, starting at €150 one-time) and voluntary donations; the core softphone remains free. Distribution is entirely direct via microsip.org with no reseller network, and growth is organic through search, word-of-mouth, and a community-driven translation platform covering 60+ languages. The project has accumulated over 10.3M downloads across standard and Lite versions since its 2008 release and is maintained by a small team (51-100 employees per firmographic data), with no disclosed external funding, parent company, or enterprise customer concentration.

Name

MicroSIP

Website

https://microsip.org

Company type

Private

Founded year

1986

Operating status

Operating

Headcount range

51–100 employees

Short description

MicroSIP is an open-source (GNU GPL v2) SIP softphone for Windows offering voice, video, messaging, and presence. Built on PJSIP, it serves office PBX users, remote workers, SIP provider customers, and small businesses via free downloads, monetized through €150+ custom branded builds and donations.

Ownership category

akta.pro rank

GTM type

B2C

Offering type

Software

Cost components

Technology or R&D, Infrastructure, Operations, Marketing or Sales

Revenue model

1. Custom Branded Builds: MicroSIP offers custom-branded softphone builds starting from €150 (one-time payment). These include branding (application name, company name, logo, icon, website links), simplified user interface, preconfigured account window and settings, additional phone lines and speed-dial shortcuts, and optional custom functionality. Single one-time payment covers unlimited installations.
2. Voluntary Donations: Users can voluntarily support MicroSIP development via PayPal or credit card. These contributions are voluntary and non-refundable with no goods or services provided in return.

Pricing tiers

Go-to-market motion1 record

Distribution channels2 records

Marketing channels4 records

Core offering

MicroSIP is a free, open-source SIP softphone for Windows that provides high-quality voice and video calling, instant messaging, presence, and standards-based SIP interoperability. Built on the PJSIP stack, the software offers broad codec support (Opus, G.711, G.722, H.264, VP8, VP9), TLS/SRTP/DTLS-SRTP encryption, and a lightweight footprint from 12 MB. The core product is distributed for free download, with revenue generated through optional paid custom-branded builds for businesses.

Product overview

MicroSIP is a single unified product offering — a lightweight SIP softphone for Windows. The portfolio consists of the main MicroSIP application (with full video support), MicroSIP-Lite (video-disabled variant for minimal resource usage), and a Custom Build service for businesses requiring branded deployments. Both MicroSIP and MicroSIP-Lite are available as installer or portable versions. The product is built on the PJSIP stack and offers voice/video communication, messaging, presence, and extensive codec support including Opus, G.711, G.722, and H.264 video.

Differentiator

Problem solved

Functional benefit

Products and services

• MicroSIP Lightweight and reliable SIP softphone for Windows providing voice and video calls, instant messaging, presence, and standards-based SIP interoperability. Designed for everyday business communication and professional VoIP use, with broad codec support (Opus, G.711, G.722, H.264, VP8, VP9) and TLS/SRTP/DTLS-SRTP encryption. Available as installer or portable version.
• MicroSIP-Lite A lighter version of MicroSIP without video support. Consumes less RAM (5-10 MB vs 10-20 MB) and has smaller unpacked size (13 MB vs 20 MB). Standalone with no additional dependencies, suited for systems where video calling is not required.
• Custom Branded Build Custom-branded softphone builds for businesses. Includes custom branding (application name, company name, logo, icon, website links), simplified user interface, preconfigured account window and settings, additional phone lines and speed-dial shortcuts, optional custom functionality, and digitally signed Windows EXE/MSI installers. Starting from €150 one-time payment covering unlimited installations.

Segments5 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration3 records

Feature10 records

Scale indicators3 records

Recent moves5 records

Expansion highlights5 records

Market position

Competitive moat4 records

Customer concentration

• Xx.com/microsipphone

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about MicroSIP