Just Share: share files and folders directly between PCs

The short version

The app sends us nothing. Just Share has no accounts of its own, no analytics, no telemetry, no crash reporting and no advertising. It does not contact us at all.
Your files go only to the people you share with. They travel between your computers, encrypted from end to end, and are not stored on any server.
Connecting directly means sharing an internet address. The people you share with, and the public network that helps computers find each other, can see your internet (IP) address.
Anything that contacts another service is optional and off until you turn it on, and this page lists every one of them.
Everything the app remembers stays on your computer.

What we collect

Nothing from the app. “We” means the makers of Just Share. We run no servers that the app talks to. The app has no sign-in, sends us no usage statistics or error reports, and does not check with us for updates. We cannot see your files, their names, your share codes, the name of your computer, who you share with, or your IP address.

Because we hold no information about you, there is nothing for us to sell, share, or hand over to anyone.

Buying the app

Just Share is sold through the Microsoft Store. Microsoft handles the purchase, the payment and the download under its own privacy statement, and we never see your payment details. Microsoft gives us sales totals and general figures about the app, such as how many copies were bought in each country, and reports of crashes that Windows collects from people who have agreed to send diagnostic data to Microsoft. None of that tells us who you are or what you share.

What the people you share with see

When you share a folder, Just Share gives you a share code for it, which works like a password for that folder. Anyone you give the share code to can connect to your computer with Just Share and ask for the folder. Unless you have turned it off for that folder, you are asked before each new person is let in to the folder’s files. Connections are encrypted from one computer to the other (the Noise protocol, as implemented by the open-source Hyperswarm libraries), so nobody in between can read them.

The people you share a folder with receive:

The folder’s contents: the files, their names and paths inside the folder, sizes, modified times and fingerprints (SHA-256), and the name you gave the share. Where the folder sits on your disk is not sent.
The name of your computer in Just Share. By default this is your Windows user name followed by “’s PC”. You can change it when you first open the app, or any time in Settings under “Your name”. Only a computer that holds the share code for one of your folders can read it.
Your IP address, and your address on your local network. Two computers cannot connect directly without these.
A device ID. This is a public encryption key made on your computer the first time the app runs. It stays the same, so people you share with can recognise your computer again. It contains nothing about you.

If you are receiving a folder

Your copy of Just Share tells the sharer how far along you are (how much you have, your speed) and sends a receipt for each file as it arrives. The sharer’s app keeps a history of who received what and when, which the sharer can export as a CSV file. That history is stored on the sharer’s computer only.

Other people receiving the same folder

People receiving the same folder can connect to each other so they can pass finished files along. They see each other’s computer name, IP address and device ID, and which of the folder’s files each one already has. Someone who has the share code but has not been let in by the sharer cannot find the other receivers this way. A receiver can turn off helping others in the folder’s settings.

Streaming and watch parties

When someone streams from a folder you share, your computer receives their requests for the videos, subtitles and pictures they open, and sends those back to them. A watch party tells everyone in the folder the host’s name, which video is playing, and where it is up to, along with the names of people who join.

Removing someone

If you remove a person from a folder, their device ID and computer name stay in your settings so the block keeps working, and the device ID is passed to the others in the folder so their computers refuse it too.

The network that connects you

To find the other computer, Just Share uses Hyperswarm’s public distributed hash table (the DHT). It is a public peer-to-peer network of computers run by many different people. We don’t run it. Its starting points are operated by Holepunch, the makers of Hyperswarm (node1.hyperdht.org, node2.hyperdht.org and node3.hyperdht.org).

Computers on that network can see:

your IP address and the port Just Share is using;
a scrambled ID for each folder you are sharing or receiving. It is a one-way scramble (a hash) of the folder’s share code, and the share code cannot be worked back out of it;
your device ID, and when you look for or announce a folder.

They are never sent your files, file names, computer name or share codes.

Are connections ever relayed?

Just Share connects computers directly. It never asks for a relay and we don’t run any. Two details are worth knowing:

Computers on the DHT pass along the short, encrypted set-up messages that let two computers behind home routers reach each other. Those messages contain no file data.
The Hyperswarm library can route a connection through a relay computer if the other person’s software asks for one. An unmodified copy of Just Share never does. If it happened, the connection would still be encrypted from end to end, and the relay could see only the two IP addresses and how much data moved.

Your computer may help the network

Like other Hyperswarm apps, a copy of Just Share that stays online for a while on an openly reachable connection can become a regular member of the DHT. It then answers small lookup messages from other people’s computers, to help them find each other. It never carries anyone’s files and never exposes yours.

Your own network

So that two computers in the same home or office can share without the internet, Just Share announces itself on your local network every few seconds while you have an active folder. The announcement contains your device ID, a port number, and scrambled tokens that only a computer already in the same folder can recognise. Other devices on the network can tell that Just Share is running on your computer. Folder names, file names and share codes are not in the announcement.

This is on by default. Turn it off in Settings under “Find computers on my network”.

Optional online lookups

If you share a library of movies and shows, Just Share can look up posters and descriptions. This is off until you turn it on, and it only ever happens on the computer hosting the library. People watching get the pictures and details from the host and never contact these services.

Service	When	What is sent
TVmaze	TV shows	The show’s title
Wikipedia	Movies	The movie’s title and year

Requests go over HTTPS straight from your computer. Each service sees your IP address and those titles, and handles them under its own privacy policy: TVmaze, Wikipedia.
Titles are worked out from your file and folder names (or a .nfo file beside a video). A video with a year in its name is treated as a movie, so a home video called “Wedding 2019” would be looked up too. Nothing else about your files is sent.
TVmaze returns details and pictures for a show. The pictures are then downloaded from the addresses TVmaze gives. Wikipedia returns a short description of a movie, and no pictures are taken from it.
Results and pictures are kept on your computer so they are not looked up again. They stay there after you turn the setting off.

Details from TVmaze and Wikipedia are used under the CC BY-SA 4.0 licence, and the library credits them with a link wherever they are shown.

Other connections the app makes

The video converter (FFmpeg) is included in the app. Nothing is downloaded for it.
Links you click. A few links (for example to a show’s page on TVmaze) open in your web browser, which then follows that site’s own rules.
Microsoft Edge WebView2. Just Share draws its window with WebView2, a Microsoft component that is part of Windows. The app only loads its own built-in pages into it and blocks everything else. WebView2 itself is maintained and updated by Microsoft and may contact Microsoft as described in Microsoft’s privacy statement. We don’t control that and receive nothing from it.
The Microsoft Store. Microsoft delivers the app and its updates under its own privacy statement.

That is the complete list. The app makes no other connections.

What is stored on your computer

Just Share keeps what it needs to work in its own data folder on your computer. None of it is sent to us.

Settings: your computer’s name in Just Share, your preferences, speed limits and schedules, and for each folder its name, its location on your disk and its options.
Share codes and keys, stored encrypted with a key that Windows protects for your user account (DPAPI).
People: for each folder, the device IDs and computer names of people you have approved, removed, or who used a limited share code. Also the computers you have marked as verified.
File lists and history: the list of files in each folder with their fingerprints, and the history of what was sent and received, by which computer and when. History is kept until you remove the folder from Just Share. No IP addresses are stored.
Library extras: downloaded posters, thumbnails and timeline frames, and how far you have watched each video.
Temporary conversion files for streaming, which are cleared each time the app starts.
A log file for troubleshooting, overwritten each time the app starts. It can contain folder names and file paths from error messages, but not share codes or IP addresses.

Where it is

All of it is inside the app’s own data folder (%LOCALAPPDATA%\Packages\, in the folder for Just Share, under LocalState). Files you receive are saved in the folder you chose (by default under Documents\Just Share) and are ordinary files that belong to you.

Deleting your data

One folder: remove it in Just Share. Its file list and history are deleted. Files you received stay where they are until you delete them yourself.
Everything: uninstalling Just Share deletes all of its data.
With us: there is nothing to delete, because we never had it.

Copies that other people already received from you are on their computers and are theirs to keep or delete. Changing a folder’s share code stops anyone else joining with the old one.

Children

Just Share is a general-purpose tool and is not directed at children under 13. We do not knowingly collect personal information from children, or from anyone else: the app collects nothing.

This website

This site sets no cookies, loads no analytics, trackers, fonts or scripts from other companies, and has no forms. If you switch between the light and dark theme, that choice is remembered in your own browser and is not sent anywhere.

Like any website, the company that hosts it may keep standard server logs, such as IP addresses and the pages requested, for security and reliability. This site is hosted by Cloudflare, which handles those logs under its own privacy policy.

Changes to this policy

If Just Share changes in a way that affects your privacy, this page will be updated and the date at the top will change. The policy that applies is the one shown here on the day you use the app.

Contact

Questions about this policy: justshare.p2p@gmail.com

Back to Just Share

Your files are yours. We never see them.