Make a free VoIP call from your browser — no SIM card, no app to install, no phone number of your own. Travelling between SIMs, using a Wi-Fi-only tablet, or just done with carrier roaming? TwinPhone calls any landline or mobile worldwide from any browser. Free signup, free test call, then from $0.02/min.
Works on any modern browser — laptop, desktop, Wi-Fi tablet, or phone without a SIM.
Most messaging apps are SIM-free but only ring other app users. Carrier calling needs a SIM. TwinPhone is SIM-free AND rings real phones.
Your home SIM is off, the local one isn't active yet, and roaming is $3/min. Open the browser, dial.
Devices without a SIM slot can finally make real phone calls — not just messages to other app users.
No subscription, no contract, no phone number you have to keep. Call when you need to, pay per minute.
A free call from a browser is a free VoIP call — “Voice over IP” just means the audio rides your internet connection instead of a cellular network. When you tap dial on TwinPhone, your browser uses WebRTC to capture microphone audio directly in the tab. That audio is encrypted with TLS for signalling and SRTP for the media stream before it ever leaves your device, so a free internet call without a SIM is no less private than a carrier call — often more so.
The encrypted stream travels to TwinPhone’s backend, which acts as a bridge between the public internet and the public phone network (PSTN/SS7). The backend hands the call off to the recipient’s carrier the same way any landline-to-mobile call is handed off today. From the recipient’s side, an ordinary phone rings with an ordinary caller ID — either a number TwinPhone owns for outbound routing, or your own virtual number if you’ve rented one. They don’t need the app, an account, or even a smartphone.
The key thing browser-based VoIP unlocks: there is no SIM, no carrier, and no phone number required on yourside. Your device only needs Wi-Fi or data and a modern browser. The recipient’s carrier handles the last mile normally, so the call quality, the ringtone, and the voicemail behaviour on their end are exactly what they expect from any incoming call.
Place and receive calls without a SIM ever touching the device. Wi-Fi or data is enough.
Chrome, Edge, Safari, Firefox — no app store, no extension, no installer.
Calls any landline or mobile, 180+ countries. Recipients don't need TwinPhone.
Free signup, free test call, then from $0.02/min. No subscription, no monthly fee.
TLS + SRTP on every call. We don't record, we don't sell call data.
Adaptive audio holds calls together in airports, hotels, and crowded networks.
Honest answers about phone calls with no SIM card.
Yes. TwinPhone runs entirely in your browser via WebRTC. There is no SIM, no phone number on your device, and no carrier involved on your side. As long as you have a Wi-Fi or data connection, you can call any landline or mobile worldwide. Recipients pick up on their regular phone — they don't need the app or a SIM either.
Yes — that's a primary use case. Open www.twin-phone.com on a Wi-Fi-only iPad, Android tablet, or laptop. Sign up free, place your free test call, then dial. No SIM tray, no eSIM activation, no carrier number required.
Yes — both phrases describe the same thing. Voice over IP (VoIP) is any phone call whose audio travels over the internet instead of the cellular network. When that VoIP call originates inside a browser tab (as TwinPhone calls do), it's called browser VoIP or browser-based calling. The technical difference vs older VoIP apps (Skype, Vonage) is that TwinPhone is a pure web app — no installer, no Chrome extension, no SIM, and the call still lands on a normal landline or mobile number on the recipient's side.
Wi-Fi calling on an iPhone or Android typically still ties to your existing SIM and carrier number — Wi-Fi is just the network path. If you remove the SIM, native Wi-Fi calling stops working on most phones. TwinPhone is true SIM-free: there is no carrier or SIM on your side at all. You sign up with an email, open the browser, and call. No phone number of your own is required to make an outgoing call — TwinPhone routes the call out for you. If you want callers to ring you back, you can rent a virtual number for $1.95/month — optional, not required.
Your browser captures audio from the microphone, encrypts it with TLS + SRTP, and sends it via WebRTC over your internet connection. TwinPhone's backend bridges that media stream onto the public phone network so the call lands as a normal incoming call on the recipient's phone. No SIM card is needed because the cellular network is never used on your side.
No — Wi-Fi calling from a phone still ties to your SIM and your carrier number, just routed over Wi-Fi instead of cellular. TwinPhone is true SIM-free calling: it does not use your SIM at all, and you don't need a phone number of your own. It's a separate calling channel on top of any device with a browser.
TwinPhone runs as a web app, so the call appears inside the browser tab on whatever device you're using. There's no native dialer integration. If you want a number that others can call you back on, you can rent a virtual number from $1.95/month — optional, not required to make outgoing calls.
Signup and a test call are free. After that, pay-as-you-go from $0.02/min to 180+ countries — no subscription, no monthly fee, no credit expiry. The exact per-minute rate is shown before every call connects so there are no surprises.
Yes. Every call leg under TwinPhone's control uses TLS + SRTP encryption end-to-end on your side. We never sell call data and we don't record calls. Adaptive audio keeps the call clear even on slow public Wi-Fi.

Free signup, free test call, then 180+ countries from $0.02/min.
$0.50 credit on signup14-day money-back guarantee