Does this use my mobile data?

No. Nothing leaves the local network, so no data is consumed even when the transfer runs over a phone hotspot.

Can I use it on a plane or somewhere with no signal?

Yes, as long as both devices join the same network. A phone hotspot creates that network without needing any signal.

Why does it not work on cafe Wi-Fi?

Public networks usually turn on client isolation, which stops devices on the network from reaching each other. Use a phone hotspot instead.

Is there a file size limit?

No. Local transfers are uncapped, and the file is streamed rather than loaded into memory, so size is limited only by the receiving device's free space.

Share files without an internet connection

A network is not the same thing as internet access. You only need the first one.

Connect both devices to the same Wi-Fi router or phone hotspot, even one with no internet behind it, and ZenShare transfers files directly between them. No data is used, because nothing leaves the local network.

Why this works with no internet

Most transfer tools send your file to a company's server and then send it back down to the recipient. That needs the internet twice, and it is why they stop working the moment you are offline.

ZenShare does not do that. The sending device runs a small web server, and the receiving device connects straight to it over the local network. The router is just moving packets between two devices in the same building. Whether that router has a working internet connection is irrelevant.

What you actually need

Two devices on the same network. A home router, an office Wi-Fi, or a phone hotspot all work.
That is the whole list. No SIM, no data allowance, no account, no signal.

A phone hotspot is worth calling out: turning one on creates a network even with mobile data switched off entirely. Devices joined to it can talk to each other, and no data is consumed.

Step by step, using a hotspot

On one phone, turn on the personal hotspot. Mobile data can stay off.
Join the other device to that hotspot.
Open ZenShare on the sending device and pick the files.
Choose the Local Wi-Fi option, not the internet link.
Scan the QR or open the link on the other device. The transfer starts.

When it will not work

Being honest about the limits saves you ten minutes of confusion:

Guest and public Wi-Fi. Cafes, hotels, airports and universities usually enable client isolation, which blocks devices on the network from seeing each other. This is a deliberate security setting and nothing on the device can turn it off. Use a phone hotspot instead.
Different networks. One device on Wi-Fi and the other on mobile data are not on the same network, even standing next to each other.
Some corporate networks apply the same isolation as public Wi-Fi.

Speed

Local transfers run at the speed of your network rather than the speed of your internet upload, which is usually the slow half of a cloud transfer. On a normal home Wi-Fi that is the difference between minutes and seconds.

Try it

Free, no account, and the person receiving the file installs nothing.

Download Zen-Share

Common questions

Does this use my mobile data?: No. Nothing leaves the local network, so no data is consumed even when the transfer runs over a phone hotspot.
Can I use it on a plane or somewhere with no signal?: Yes, as long as both devices join the same network. A phone hotspot creates that network without needing any signal.
Why does it not work on cafe Wi-Fi?: Public networks usually turn on client isolation, which stops devices on the network from reaching each other. Use a phone hotspot instead.
Is there a file size limit?: No. Local transfers are uncapped, and the file is streamed rather than loaded into memory, so size is limited only by the receiving device's free space.