Overview

Blink connects to SIP providers, SIP2SIP and Bonjour devices on a local network. It supports multiple SIP accounts and can sync accounts between computers through iCloud. A SIP account is required to use the client, though users can sign up for one through SIP2SIP within Blink.

The combination of calling, chat, file transfer and screen sharing makes Blink more than a basic softphone. That breadth comes with a compatibility caveat: features can differ by operating system and version, and some conferencing functions require a conference server. See the Softphone Software directory for other options.

Key features

Calling and collaboration

Blink supports voice and video, with Opus audio, H.264, VP8 and VP9 video codecs, and acoustic echo cancellation. ZRTP provides encrypted media. Screen sharing can accompany audio, and conferences can combine VoIP, instant messaging, presence, file transfer and screen sharing, with participant management. This is a capable mix for teams whose SIP and conference-server setup supports it; it is less compelling if you need every function to work independently of your environment.

Messaging, files and contacts

Chat sessions use MSRP, with OTR end-to-end encryption support. SIMPLE presence and XCAP server storage extend messaging beyond one-to-one chat. File transfers use MSRP and TLS encryption, with progress reports and delivery confirmation. OpenPGP messaging support is also listed. Contact discovery can draw on the system address book, LDAP directories and Bonjour neighbours, while web pages can provide caller information.

Accounts and privacy

Multiple SIP accounts are supported, and iCloud syncing can carry account settings between computers. Blink says it does not collect data from end-users; users of its built-in SIP2SIP accounts are directed to SIP2SIP's privacy information. That distinction matters: the client’s privacy statement does not describe the handling of an external SIP provider’s account.

Pricing

Blink is freemium, with a free plan at no cost. The Blink plan provides Linux, Mac and Windows downloads, but it still requires a SIP account for use. It is the sensible starting point for individuals or teams that already have compatible SIP service; the free download is not a bundled calling service.

Blink Pro has custom pricing. Discounted pricing is available for organizations with more than 100 seats, and AG Projects says it can provide demonstrations and enterprise integration support for organizations at that size. That makes Pro the route to explore for larger deployments, rather than a priced self-serve upgrade. No seat minimum or other plan limits are established for Pro.

Platforms

Blink is listed for Android, iOS, Linux, macOS, web and Windows, and browser calling and mobile and desktop apps are supported. The download page offers Mac, Windows and Linux versions, with Debian and Ubuntu installation instructions for Linux. Since feature availability may vary by operating system and version, readers choosing a specific platform should confirm that it supports the functions they depend on.

Who it's for

Blink is best suited to SIP users who want a single client for calls, messaging, file transfers and screen sharing, and who can manage their own service account. Its account flexibility and range of collaboration features also make it worth considering for larger organizations evaluating SIP integration. It is not the right choice for someone who expects free software to include phone service, or for a team whose conferencing needs depend on functions unavailable in its server setup.

Pros and cons

Pros: Calls, messaging, file transfers, screen sharing and conferences sit in one SIP client, reducing the need to assemble separate tools for those tasks.
Pros: ZRTP, OTR and TLS cover media, chat and file-transfer encryption respectively, with OpenPGP messaging support as an additional option.
Pros: Multiple SIP accounts, iCloud syncing and account sign-up through SIP2SIP offer several ways to manage access.
Cons: A separate SIP account is required, so the free plan does not provide calling service by itself.
Cons: Some conferencing features need a conference server, and platform or version differences can affect what users can do.
Cons: Blink Pro uses custom pricing, making it less straightforward for organizations that need a published per-seat cost before evaluating it.

Alternatives

Linphone is the stronger candidate if open-source licensing matters: it is available across Android, iOS, Linux, macOS, web and Windows, and can be integrated under the GNU GPLv3 license, with proprietary licensing available for closed-source projects.

Siperb Mobile Softphone is worth comparing if you want a free personal tier with community support; its Personal plan has limited storage, seven-day SIP Trace Logs and Register Activity Logs, and no technical support.

SipPulse Softphone may suit teams looking for a free app plan with unlimited users and installations, available for iOS, Android, Windows and Linux.

Zoiper is an option for non-commercial use if one account and two lines are enough; its Zoiper 5 Free plan is free.

SessionTalk Softphone is a paid-team alternative with a published Teams Phone plan at 20.00 USD per month, including five seats, with additional seats at $3 each.

Softphone.Pro is another paid alternative, with pricing shown per user per month and monthly or annual billing choices.

Browser Phone is a free, open-source project for readers who want a web-only, self-hosted option.

AGEphone is another freemium alternative available on Windows, iOS and Android.

Verdict

Choose Blink if you already have SIP service and want calling, messaging, file transfer and screen sharing together, particularly if your organization can make use of AG Projects’ enterprise integration support. Look elsewhere if you need bundled phone service, predictable Pro pricing or conferencing that does not depend on a compatible server.

	Blink	Siperb Mobile Softphone
Free plan	Yes	Yes
Paid from	Free	£2/mo
Platforms	Android, iOS, Linux, macOS, Web, Windows	Android, iOS, Linux, macOS, Web, Windows
Free plan	Yes	Yes
Browser calling	Yes	Yes
Mobile app	Yes	Yes
Desktop app	Yes	Yes
Call recording	Yes	Yes
SIP support	Yes	Yes

Blink vs Siperb Mobile Softphone

Blink

Siperb Mobile Softphone