What is a softphone, and how is it different from a web phone?

What is a softphone?

A softphone is software that turns a computer, tablet or smartphone into a phone. You install it, sign in to a calling provider, and get a dial pad, contacts, hold and transfer through your microphone and speakers or a headset. Calls travel over the internet as VoIP, and the provider connects them to landlines and mobiles.

There are two kinds. Provider apps work only with their maker's accounts, like Zadarma's apps for Windows and macOS^[6] or Aircall's desktop app^[4]. Generic SIP softphones work with any provider that issues SIP credentials: MicroSIP says it can "connect to any SIP provider or PBX system"^[1], and Linphone accepts its own free account or one you bring^[7].

Skype was the softphone many people knew, until Microsoft retired it on 5 May 2025^[8]. What became of Skype and its credit is a separate story.

What is a browser phone (web phone)?

A browser phone is a web page that works as a phone. You open the provider's site, sign in, allow the microphone and dial. The browser's built-in WebRTC carries the audio with no plug-in or download^[9], and the provider bridges the call to the public telephone network. Close the tab and the phone closes with it.

Yolla Web needs no download, install or update^[10], and TwinPhone signs you up with an email or Google account and runs in current Chrome, Edge, Firefox, Brave and Safari^[11]. Business services have web phones too, such as Quo's web app^[12] and Zadarma's WebRTC calling from its personal account^[6].

A page gets the microphone only on a secure (HTTPS) connection and after you allow it^[13]. Incoming calls depend on the service: TwinPhone rings in its browser tab or iPhone app, one of which must stay open or signed in^[14], while Yolla Web makes outbound calls only^[10].

Softphone vs browser phone: what actually differs?

The voice path is much the same: audio goes over the internet to a provider that reaches the phone network. What differs is everything around that path. I compared the points below in the providers' own help pages and the IETF standards on November 1, 2026.

Some providers offer both: Zadarma has its own apps, a setup guide for the third-party MicroSIP softphone^[2] and WebRTC calling from its personal account^[6]. The wider app-versus-browser question, beyond softphones, is in calling from a browser or from an app.

What is a SIP account, and do you need one?

A SIP account is the set of credentials that lets a SIP-compatible phone or app sign in to a provider: a server address, a login and a password. SIP, the Session Initiation Protocol, is the IETF standard for setting up and ending calls^[17]. Generic softphones and desk IP phones need one; consumer browser phones such as TwinPhone use their own email or Google login^[11].

Setting up a softphone with a SIP account

1. Open an account with a SIP provider. Zadarma gives new accounts a free internal SIP number and a free echo test on 4444^[19].
2. Install a SIP softphone, such as MicroSIP^[1] or Linphone^[7].
3. Add an account with the provider's three values. In Zadarma's MicroSIP guide they are the server sip.zadarma.com, your SIP number as login^[2], and that number's own password^[2].
4. Save. If the details are right, the status shows Online^[2], which means the app has registered.
5. Call the echo test, then add credit: calls to phone numbers are charged^[19].

The free SIP number is internal to the provider's network^[19]. To show a real phone number to the people you call, you buy a virtual number and set it as your caller ID^[20]; Zadarma lists numbers in 110 countries^[21].

Can a browser phone use SIP?

Yes. An IETF standard runs SIP over WebSocket "to enable use of SIP in web-oriented deployments"^[22], while WebRTC carries the audio. Consumer web dialers such as Yolla Web and TwinPhone do not ask for SIP credentials; they run on their own accounts and balances^[10][23].

Pros and cons of softphones and browser phones

Beyond the table, the trade-offs come from one root difference: a softphone is a general tool you configure yourself, while a browser phone is one provider's service that you sign in to. That makes the softphone more flexible and the browser phone quicker to start. These are the points I would weigh, taken from the providers' own documentation.

Softphone

• Pro: free clients exist: Linphone is free on desktop and in the app stores^[7], and MicroSIP is open source under GNU GPL v2^[1].
• Pro: you can change provider and keep the same app^[1].
• Con: one typo in the server, login or password and it stays offline^[2].

Browser phone

• Pro: it can run on a Chromebook or Linux, as TwinPhone says its dialer does^[11].
• Con: you are tied to one provider's page, rates and balance.
• Con: some routers and firewalls block direct WebRTC connections, and the audio is then relayed through a server^[24].

What does each cost to run?

The client is rarely what you pay for: Linphone is free^[7], MicroSIP is open source^[1], and a browser phone costs nothing to open. You pay for calls to phone numbers and for any number you rent, and the balance belongs to the account rather than the client: Yolla Web runs on the same account as the Yolla mobile app^[10]. Three providers' published rates per minute:

Per minute, lowest published rate on the date checked. Scroll sideways on a phone.

Zadarma's rates exclude VAT^[25], and from 10 November 2026 its US calls are billed with a 12-second minimum, then per second^[30]. TwinPhone rounds up to whole minutes and its credit does not expire^[23]; it has no free calls or trial credit^[31] and charges more than Yolla for UK and Indian mobiles^[26][28][29]. Business phone systems are often sold per seat: Dialpad starts at $15 per user a month, billed annually^[32].

Which should you use?

Choose by situation, not by technology. A browser phone is the shorter path for a few calls a month from a laptop. A softphone fits all-day calling, existing SIP credentials from an employer or provider, or one app across several providers. The two can coexist: a softphone for work and a browser phone for the odd personal call.

• Occasional calls to real numbers: a pay-per-minute browser phone; my full comparison of browser calling services lists rates and sign-up rules.
• A locked work laptop, a Chromebook or a borrowed computer: a browser phone that supports your browser.
• All-day calling, an office PBX, or frequent provider changes: a softphone with SIP credentials, such as MicroSIP or Linphone.

Frequently asked questions

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