PairOnce

DIFFERENT NETWORKS · MOBILE DATA

Send files between a phone and a computer that are not on the same Wi-Fi

Yes, it works: open paironce.com on both devices and pair them; the phone can be on mobile data and the computer on any other network, as long as both are online.

PairOnce first tries a direct connection; if a network blocks it, the files go through an encrypted relay, and the status bar shows how much of the month’s 200 MB relay allowance is left.

For big files, connect the computer to the phone’s hotspot: both are then on one network and the transfer goes direct, with no relay limit.

Step by step

  1. Get both devices online. Wi-Fi, mobile data or a wired network, any combination. Both need the internet to find each other.
  2. Pair them. Open paironce.com on the computer and scan its QR code with the phone, then check the safety code and click Approve device. A page opened from a QR code or link asks you to confirm first: tap Connect.
  3. Look at the status bar. Encrypted · direct means no limit beyond the file size. Encrypted · relayed shows what is left of the month’s relay allowance.
  4. Send. Tap Choose files, accept and save on the other side. A file larger than what is left on the relay is refused before anything is sent, with a note to use one network.

The hotspot trick

Turn on the phone’s personal hotspot and join it from the computer. The two devices are now on the same small network, so PairOnce connects directly: the file goes straight across the hotspot link, and usually only the brief connection setup uses mobile data.

All PairOnce needs is an internet connection on each device, mobile data included: the two devices find each other through paironce.com and then connect.

Limits, and when this is not the right tool

  • A file can be up to 2 GB over a direct connection when the receiving browser saves straight to disk (Chrome or Edge on a computer or Android, Firefox on a computer, Safari on iOS 26 or later). Other browsers take up to 50 MB per file and hold 100 MB of received files at a time.
  • Files over 2 GB need PairOnce Pro on one of the two devices. Then a file can be up to 10 GB, received the same way, and the relay carries 5 GB a month.
  • When the two devices cannot reach each other directly, an encrypted relay carries the data. Each device can send and receive 200 MB a month that way, counted together; a direct connection has no monthly limit.
  • Both pages must stay open until everything has arrived: keep the phone’s screen on and the browser in front.
  • PairOnce moves things between two devices that are open at the same time. It is not cloud storage: nothing waits on a server for later.

Other ways to do it

  • A cloud drive. Made for different places and networks; it uploads first and downloads later, so it is slow for large videos and needs an account.
  • Quick Share or AirDrop. Work without a shared Wi-Fi, but only between Android and Windows, or between Apple devices.
  • A USB cable. Needs no network at all, if you have the right cable and the computer can read the phone.
  • Email or a messaging app. Fine for small files; attachments are limited and photos are often compressed.

Common questions

Why did it say “relayed”?

One of the networks (often mobile data, a company or a school network) blocks direct connections. The relay forwards only encrypted data; it cannot read files or messages.

What happens when the relay allowance runs out?

PairOnce stops relaying for that device until the next calendar month and asks you to put both devices on one network, where nothing is counted.

Does the relay use more mobile data?

No more than the file itself: the bytes go once through the relay instead of directly.