MicroSIP (Lite) is a compact, portable SIP softphone for Windows that makes voice and video calls, chats and shares presence through any standard SIP provider, with almost no disk footprint and no installation required.
MicroSIP (Lite) registers directly with a SIP provider or PBX and then behaves like a normal phone on the desktop. You enter the account details once, and the client keeps that registration alive, showing contacts, presence and call history in a single window with a keypad underneath. Outgoing calls go to extensions, numbers or SIP addresses, while incoming ones pop up over other windows with answer and decline buttons. Chat messages travel over the same account, so a quick question does not need a phone call. The project publishes both a full build and a lighter one, and MicroSIP (Lite) is aimed at people who want the smallest workable installation for everyday office calling.
Because it is built on the PJSIP stack, MicroSIP (Lite) interoperates with mainstream SIP infrastructure rather than tying users to one vendor: Asterisk and FreePBX systems, commercial PBXs and hosted services such as OnSIP all register it without special configuration. Administration is equally undemanding. Settings live in an INI file next to the executable, so a working configuration can be copied to another machine or carried on a USB stick, and accounts, shortcuts and call logs can be exported and imported wholesale. That portability makes MicroSIP (Lite) attractive for technicians and support desks who need a known-good softphone they can drop onto an unfamiliar PC and remove again without leaving traces behind.
The reasons people keep MicroSIP (Lite) on a workstation are practical rather than glamorous. It starts quickly on modest hardware, uses very little memory, and needs no runtime or framework installed beforehand, which matters on locked-down machines where installing software is an event. Call handling covers the everyday essentials without hunting through menus: hold, mute, blind and attended transfer, forwarding, and a dial plan that rewrites numbers before they leave the phone. Call recording captures conversations to local files, either automatically for every call or on demand, and those recordings travel with the rest of the configuration. Presence indicators and busy lamp fields show who is free before you dial. Accessibility has been treated seriously too, with screen reader support, a translated interface and right-to-left layouts, so MicroSIP (Lite) stays usable well beyond the standard office desktop.
Key capabilities and highlights.
MicroSIP (Lite) runs from a folder without a formal installation, keeping its configuration in an INI file beside the executable. A known-good setup can be copied to another PC or carried on a USB stick, which suits technicians and anyone who works across several machines.
Place high-quality voice calls and switch on video when a conversation needs it, with H.264, H.263+, VP8 and VP9 codecs available. Audio support ranges from Opus and G.722 down to narrowband options such as G.729, so the client can match whatever the far end supports.
SIMPLE messaging and presence keep quick text exchanges and availability inside the same account as calls. Colleagues can see who is already on the phone before dialling, and busy lamp field indicators make shared lines and call pickup straightforward on Asterisk-based systems.
TLS protects SIP signalling, while SRTP and DTLS-SRTP encrypt the media stream itself. Nothing extra has to be purchased to use them, which makes the client a sensible choice for businesses that need call privacy without adopting a heavier unified communications platform.
Hold, mute, blind and attended transfer, call waiting and reject-with-reason cover the mechanics of a normal working day. A dial plan rewrites or prefixes numbers before dialling, and answering calls automatically based on caller number helps operators taking traffic from a fixed queue.
Record every call automatically in MicroSIP (Lite) or start recording on demand, with files saved at the original sampling rate and MP3 output available. Keeping recordings local means no subscription is required, and the files can be archived wherever your retention policy points.
Contacts can be imported and exported as CSV, searched by number and annotated with extra details, while the call log records who rang and for how long. A users directory can pull entries from the PBX, so shared numbers appear without anyone typing them in.
Screen readers such as NVDA work with the interface, the codec list can be managed from the keyboard, and MicroSIP (Lite) ships translated with right-to-left support. Multi-monitor and DPI scaling settings keep the window readable on high-resolution displays and mixed screen layouts.
Browse historical releases and previous builds.
Common questions about MicroSIP (Lite).
It is a free, open-source SIP softphone for Windows built on the PJSIP stack. The Lite build sits alongside the full version and shares the same calling, contacts and account handling in a smaller package.
No. A portable archive is published for the builds, and the client stores its settings in an INI file next to the executable, so it can run from a normal folder or a removable drive.
Any SIP-compliant service or PBX should work, including Asterisk, FreePBX, commercial systems and hosted providers. You need account credentials and, where required, the proxy or STUN details from that provider.
Video is supported using H.264, H.263+, VP8 and VP9 codecs, and it can be turned off in settings when it is not wanted. Camera permission is checked before a video call starts, which avoids frozen windows on laptops.
Yes. TLS can secure SIP signalling and SRTP or DTLS-SRTP can protect the media, provided the other endpoint supports the same options. Both settings live in the account preferences of MicroSIP (Lite).
Yes. Recording can be enabled for all calls or started manually, with MP3 output available. Files are written locally, so no external storage account or subscription is involved in capturing the conversation.
Screen readers such as NVDA work with the interface, codec lists can be managed from the keyboard, and the application is translated with right-to-left layout support for a range of languages.
It is deliberately small, loading in a few megabytes and requiring no external dependencies, which is why MicroSIP (Lite) runs comfortably on older machines and on virtual desktops used purely for call handling.
MicroSIP (Lite) is a compact, portable SIP softphone for Windows that makes voice and video calls, chats and shares presence through any standard SIP provider, with almost no disk footprint and no installation required.
MicroSIP is a lightweight open-source SIP softphone for desktop voice and video calls, built on the PJSIP stack and compatible with standard PBX systems and VoIP providers. It suits offices and support desks that want dependable calling, presence, and messaging without heavy software.
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