Basics
Do I need an account?
No. There's no sign-up, email or phone number. Two devices trust each other because you paired them with a QR or VW- code and checked the 6-digit number.
Which devices does it run on?
Windows, Android and Linux, plus a browser extension for Chrome, Edge, Brave and Firefox. On Linux there's a .deb for Ubuntu 22.04+ and Debian 12+, and an AppImage. There's no macOS or iOS app. You can pair any two: PC with phone, PC with PC, or phone with phone.
What can I send?
Web links, text, your PC's clipboard text, and files or photos. Links open in your PC's default browser. Files are only saved after you accept them on the receiving device, and programs are never run automatically.
Does it cost anything?
No. The apps are free and open source, and so is running your own relay. The public relay is run by the Voidwire project and is free while costs allow, under a few rules.
Managed relays are an optional paid service for people who want a private relay without running a server. You never need one. See pricing.
Relays
Does it work when I'm away from home?
Yes. On the same network, devices connect directly. Otherwise they go through a relay, still encrypted end to end. By default files up to 25 MB go through the relay, and the app asks before sending anything over 256 KB that way.
What if the other device is off or asleep?
Links and text wait for it on the relay, encrypted and in RAM only, for up to 60 minutes by default, and arrive when it next connects. Files need both devices online.
What's a managed relay?
A relay and mailbox that the Voidwire project runs for your devices only, with token access, so you get your own relay without running a server. You add it in the apps with a relay link, the same way as a self-hosted one.
Like any relay it can't read what you send, but it sees IP addresses and timing. If you want that metadata to stay with you, run your own. Plans start at $79 a month. More about managed relays.
Can I run my own relay?
Yes, for free, with Docker or plain binaries on a Linux host. See Self-host a relay. You can use more than one relay, and each pairing can sit on a different one.
Can I put my relay behind Cloudflare Tunnel?
We don't recommend it. Cloudflare would terminate TLS and see who connects to whom, when, how much, and your access token. It also doesn't carry UDP. A DNS-only record is fine. Why.
Privacy & safety
Why did a link open on my PC by itself?
That's the default: links from your paired devices open right away. If you'd rather approve each one, turn on Ask before opening in the desktop app's settings. It shows the website and the sending device first.
Why doesn't Voidwire show Windows notifications?
Windows stores notification text in a database on disk. A notification like "Opened example.com from Phone" would leave a record of what you opened, so the desktop app shows none.
Does Voidwire keep a history?
Not unless you ask. Recent sends, the last device you used, file history and the diagnostics log are all off by default. Turn one off and its data is deleted.
I lost my phone. What do I do?
On your PC, open Devices and choose Forget on that phone. Your PC refuses it from then on. Anyone holding the unlocked phone could otherwise keep sending to your PC.
Has it been audited?
Not yet. Voidwire hasn't been independently audited. The protocol spec, the threat model with its known weak points, and all the code are public on GitHub. If an audit happens, we'll publish the report and link it here.
Does the app contact anything on its own?
Only to check for updates. At most once a day, each app downloads a small signed file from GitHub Pages to see if there's a new version. It sends no device ID or anything about your devices; GitHub sees your IP address and the time. Turn it off in Settings → Updates. More.
How do I report a security issue?
Email security@voidwire.app, privately first. See reporting a security issue.
Installing
Why does Windows say it protected my PC?
SmartScreen can warn about apps that few people have downloaded. Check the checksum on the download page, then choose More info → Run anyway. The installer isn't code-signed, which is why the warning names no publisher.
How do I install the browser extension?
Download it from the download page and load it as the page explains. On Edge, get it from Microsoft Edge Add-ons; it isn't in the Chrome Web Store or Firefox Add-ons yet. It needs the desktop app on the same PC.
Where are the release notes and older versions?
On the GitHub releases page. The current release is 1.1.0.