Overview of Free SIP Clients for Windows
We selected the seven most popular customers and used each of them for one day.
1) X-lite
For most people, this was the first SIP client they met. Four years ago, there seemed to be no better alternative. Previously (and even now for many) it looked like this:

Time passed and it was combed, tinted and pumped with silicone proteins - now it requires Microsoft NET Framework4 and Microsoft Visual C ++ during installation.

He really became fat, both in the consumption of resources and in the size of the window; against his background, the rest of the clients seem fit athletes.

And advertising in the free version (offering to switch to the paid version) has not gone away. There is a suspicion that CounterPath uses X-Lite to break in its main product, Bria, which greatly affects the stability of new versions, and for communication this is a critical indicator. We were also very disappointed when we could not call another domain, since it does not support direct calls. X-lite is no longer a cake.
2) Blink
Like X-Lite, Blink has two versions, free (stripped down) and paid. For example, in the free version, the call transfer function is cut, which makes it impossible to use the free version in the office. And for private use, even nothing.

3) MicroSIP
From the name it’s immediately clear what kind of client it is, it’s really very light, after installation it takes up only 2.5 MB and consumes only 5-12 MB of RAM in the process. There is support for video h264 and h263 +. This is exactly the case when the name accurately characterizes the program.

This client will appeal to many.
4) 3CX Phone
Many probably he is already familiar, in general, he is good, has all the necessary functions for working with him in the office. He has a chip that distinguishes him favorably, these are BLF buttons, unfortunately the first time we were not able to get them to work with our service, there will be time to try to figure it out.

5) Zoiper
There are versions for almost all operating systems. Like the first two SIP clients, it has a paid version, for example, when trying to transfer a call, a notification pops up from the floor of the screen about the inaccessibility of this function and opens a page with an offer to buy a license. Work on it really did not work.


6) Linphone
Opensource project, now they are focused on mobile clients, and the desktop version

7) SJ Phone
A good idea, there is everything you need, but it has been almost six years since it was not updated (XPsp2, v.1.65.377a, 03/20/07 (NEW!)), A lot of bugs. You can use it, but nothing good will come of it.

Summary table
| Phonerlite | X-lite | Blink | Microsip | 3CX Phone | Zoiper | Linphone | SJ Phone | |
|---|---|---|---|---|---|---|---|---|
| Ability to use multiple accounts at the same time. | - | - | + | - | + | 2 | + | - |
| The number of simultaneously processed calls | 8 | 2 | > 20 | > 5 | 5 | 2 | unlim | unlim |
| The number of participants in the local conference | 8 | 2 | > 20 | 0 | 5 | - | + | unlim |
| Encryption | SRTP, TLS, zRTP | - | SRTP | + | TLS, SRTP | TLS, SRTP | SRTP, ZRTP | - |
| Codecs | G711A / U, GSM, iLBC, Speex, G722, OpusG726 | G711A / U, GSM, iLBC, BV-32 | G711A / U, GSM, iLBC, Speex, G722 | G711A / U, GSM, iLBC, Speex, G722, G729, SILK | G711A / U, GSM, Speex | G711A / U, GSM, iLBC, Speex, G726, | G711A / U, GSM, iLBC, G722, SILK, G729. | G711A / U, GSM, iLBC |
| Video support | - | + | + | + | + | ± | - | - |
| License | freeware | freeware | freeware | opensource | freeware | freeware | opensource | freeware |
| Hotkeys | + | + | + (fixed) | - | - | - | - | + |
| Advanced contact management | google contact, CSV | Csv | google contact | - | - | various web services | - | + |
| Convenience of everyday use (subjective assessment) | 5 | 2 | 4 | 5 | 4 | 2 | 3 | 3 |
To summarize:
If you need a SIP client for work, then you should look towards 3CX Phone, Phonerlite.
And for private communication - Blink and MicroSIP.
This is not the whole list of SIP clients, in the future we will do more reviews.
Choose you, there is a good choice.