Overview

Blink is a SIP-based communications client for people who want calling, messaging, file transfer and conferencing in one application. It suits individuals and organizations already using SIP services; its breadth is appealing, but it is not a standalone calling service.

Multiple SIP accounts, encryption options and conferencing tools make Blink more than a basic softphone. The trade-off is that use depends on an account from a SIP provider, and features vary by platform and version.

For a broader comparison, see our Softphone Software list.

Key features

Calling, video and conferences

Blink supports Opus audio, H.264, VP8 and VP9 video, and acoustic echo cancellation. ZRTP protects media, while screen sharing can accompany audio. Conferences can combine VoIP, instant messaging, presence, file transfers and screen sharing, with participant management. That range can suit teams coordinating through SIP, but some conference features require a conference server.

Messaging, transfers and contacts

MSRP chat, SIMPLE presence and XCAP server storage cover core messaging needs; OTR and OpenPGP support add encrypted-chat options. File transfers use MSRP and TLS, with progress reports and delivery confirmation. System address book access, LDAP search, Bonjour neighbours and caller information from web pages offer several ways to work with contacts.

Accounts and privacy

Blink handles multiple SIP accounts, can sync accounts between computers through iCloud, and offers sign-up for a built-in SIP2SIP account. The client says it does not collect end-user data; users of its built-in SIP accounts are directed to SIP2SIP's privacy information. Call recording is also supported.

Pricing

Blink: 0.00 USD per free. Linux, Mac and Windows downloads are free, but a SIP account is required to use the client. This is the clearest fit for individuals who already have SIP service and want the desktop feature set without a software charge.

Blink Pro: custom pricing. Discounted pricing is available to organizations with more than 100 seats, and AG Projects offers demonstrations and enterprise integration support to organizations above that threshold. This route is aimed at larger deployments; it is not a published per-seat plan for smaller teams.

Platforms

Blink is listed for Android, iOS, Linux, macOS, web and Windows. The download page provides Mac, Windows and Linux versions, including Debian and Ubuntu installation instructions. Feature availability varies by operating system and version, so users should confirm that their needed capabilities are supported on their chosen platform.

Who it's for

Blink is a sensible choice for SIP users who want voice and video alongside chat, transfers and screen sharing, especially when encrypted communication options or multiple accounts matter. It is less suitable for someone seeking a calling service that works without a SIP account, or a team that needs identical conferencing features on every platform.

Pros and cons

Pros: The free desktop plan combines voice, video, messaging, file transfers and conferencing, making it useful beyond basic calling.
Pros: ZRTP, OTR, TLS and OpenPGP support provide distinct security options across media, chat and transfers.
Pros: Multiple accounts, iCloud syncing and directory integrations help users work across accounts and contact sources.
Cons: A SIP account is required, so the free client does not supply calling service by itself.
Cons: Feature variation by platform and version, plus server requirements for some conference functions, can complicate deployment.

Alternatives

Linphone is worth choosing if open-source licensing is important, or if you need its broader platform set, including API and self-hosted options.

Siperb Mobile Softphone offers a free Personal plan with limited storage, seven-day SIP Trace and Register Activity logs, community support and no technical support; choose it if those stated limits fit your needs.

SipPulse Softphone has a free App SipPulse plan for iOS, Android, Windows and Linux with unlimited users and installations; consider it if that user and installation allowance is the priority.

Zoiper offers a free non-commercial Zoiper 5 plan limited to one account and two lines, a better fit when that narrower setup is sufficient.

SessionTalk Softphone may suit teams seeking a paid Teams Phone plan with five seats included and extra seats at $3 each.

Softphone.Pro is another option to compare for a paid subscription, with selectable monthly or annual billing and terms of one, six or twelve months.

AGEphone is an alternative with a free plan on Windows, iOS and Android.

Halcyon is a free alternative for Android and Linux.

Verdict

Choose Blink if you already have SIP service and want a free client that brings calling together with messaging, transfers and conference tools, backed by multiple security options. Look elsewhere if you need calling without a separate SIP account or require the same conference capabilities across platforms.

	Blink	Sipdroid
Free plan	Yes	No
Free trial	No	No
Paid from	Free	—
Open source	No	No
Platforms	Android, iOS, Linux, macOS, Web, Windows	Android
Free plan	Yes	Yes
Browser calling	Yes	—
Mobile app	Yes	Yes
Desktop app	Yes	—
Call recording	Yes	Yes
SIP support	Yes	Yes

Blink vs Sipdroid

Blink

Sipdroid