What do I need to call a phone from a computer?
You need a computer with a browser, a microphone and an internet connection — nothing else. A laptop's built-in microphone and speakers work; a headset helps in a noisy room but is not required.
TwinPhone runs on Windows, macOS, Linux and ChromeOS because it runs in the browser, so there is no installer, no softphone to configure and no SIP account to set up. It also does not need a SIM card or a phone number of your own: you call from an account, not from a line, which is why it works on a desktop that has never had a phone attached.
Supported browsers are Chrome, Edge, Firefox, Brave and Safari. Calls adapt to the connection they get, so hotel and café Wi-Fi is usually fine; a wired or 5 GHz connection is better for long calls.
Can people call my computer back?
Yes, if you rent a number. A TwinPhone number is a real US or Canadian phone number from $3.19/month, and when someone dials it the call rings in your browser tab — or in the iPhone app if you are away from the desk.
Without a rented number you can still make outbound calls, and the people you call see a TwinPhone caller ID. With one, your outbound calls show your rented number, so the person can simply call it back. Rented numbers also receive incoming texts from US and Canadian senders in the same inbox. See virtual numbers for what the number can and cannot do.
Does the person I call need anything?
No. The person you call answers on their ordinary landline or mobile and needs no app, no account and no internet. That is the difference between calling from a computer through TwinPhone and calling through WhatsApp, Telegram or FaceTime, which only reach other users of the same app.
It also means you can call businesses, government lines, hotels and anyone whose number you have — not only contacts who happen to use a particular app.
Is calling from a computer free?
Signing up is free and there is no monthly fee, but the calls themselves are paid per minute. Genuinely free computer-to-phone calling does not exist for calls that terminate on the public phone network, because the receiving carrier charges for every answered minute.
What you get instead is a low, visible rate: $0.02/min to the US and Canada, and the exact figure for any other country shown before the call connects. Free apps that advertise computer calls are either app-to-app only or ad-supported with limited destinations.
Computer or phone app — which should I use?
Both, if you like: the browser and the iPhone app share one account and one balance, so a call started at the desk and a call made from the street cost the same and show up in the same history. Android users call from the browser.
The computer is the better tool for long calls, for dialling while you have documents open, and for anyone whose phone has no SIM or no signal. The app is better on the move. Nothing has to be chosen once.
Why does a browser call sound different from a chat app?
TwinPhone uses WebRTC, the same real-time audio standard video-meeting tools use, and connects it to the public phone network. Audio is encrypted between your browser and TwinPhone with TLS and SRTP, and the codec adapts to the bandwidth available rather than dropping the call.
The far end is a normal phone line, so the call sounds like a phone call — not like a video meeting — and the other person's experience is identical to being called from any phone.
