Kinzo for Windows

1. Getting started

Install Kinzo for Windows from the Microsoft Store, and Kinzo for Android from Google Play on your phone. Kinzo for Windows talks to Kinzo on your phone — on its own it has nobody to talk to.

• Windows 10 (version 1809) or Windows 11, 64-bit
• Kinzo 1.2 or newer on the phone
• The PC and the phone on the same network — the PC can be wired, as long as it is the same router

First run

Kinzo asks what to call this computer. That name is what other devices see when they look for you — it is not your Windows account name. It starts as this PC’s own name; change it to something like “Windows PC” if you would rather the real name stayed private. You can change it later in Settings.

The main window has three tabs on the left — Trusted (devices you have paired with), Available (devices found on the network) and Chats (your conversations) — and the open conversation on the right. Along the top are Connect to a device, a refresh button and the Settings gear. The status line at the bottom says which port Kinzo is listening on.

2. Pairing with your phone

Both devices need Kinzo open and to be on the same network.

1. Open the Available tab. Devices on the network appear there by themselves.
2. Click the device, then Pair.
3. Both screens show the same six-digit code. Check they match, then accept on both.

Pairing works just as well the other way round: open Available on the phone, tap Pair beside your PC, and accept here.

Once paired, the device moves to Trusted and you can message it. Each device remembers the other’s key, so pairing is a one-time step.

3. If nothing appears

Some networks block the ways devices announce themselves. In order of effort:

• Search this network — the button on the empty Available tab. It tries every address on your network in turn. Slower, but it works where announcements are blocked.
• Connect to a device — the button at the top. Type the phone’s address, which it shows on its own This device card, for example 192.168.1.19.
• Let the phone scan this PC — open Settings here and, on the phone, go to Available → Connect by IP → Scan QR code, and hold it up to the code. It carries every address this computer can be reached at, so the phone picks whichever one it can actually reach, and it connects and pairs in one step. Kinzo for Windows has no camera scanner of its own; this is the direction that works.

Also worth checking:

• Both devices are on the same Wi-Fi network. A Wi-Fi extender with its own name is often a separate network, and devices on it cannot see the main one.
• The phone has Kinzo open, or Receive in background switched on.
• The firewall banner is not showing here — see Being reachable.

4. Messaging

Pick a device from Trusted or Chats and type.

Under each message you send:

Messages you write while a device is away are kept and sent when it comes back. You do not have to be connected to write.

Try sending again is for when you know the device is back and do not want to wait. If it is not connected, Kinzo tries to reach it first, and tells you if it cannot.

5. Stickers & emoji

The smiley beside the paperclip opens the Kinzo sticker pack, the same 24 stickers the phone has. Click one to send it. Stickers from the phone appear here as stickers: no bubble, with the time underneath.

A message that is only one, two or three emoji is shown large and without a bubble. Windows draws them in black and white, not colour.

6. Sending photos, videos & voice notes

Three ways:

• Drag files onto the conversation.
• Paste with Ctrl + V — a copied file, or a picture such as a screenshot.
• The paperclip beside the message box.

Progress is shown while a file moves; large files travel in pieces.

7. Receiving & the viewer

Photos appear in the conversation, and voice notes play in place. Click any photo or video to open Kinzo’s own viewer:

Right-click a message that has a file for Open, Save as… and Show in folder.

Kinzo shows photos and video itself rather than handing the file to another program, because a file that arrived over the network should not need another application opened on it just to be looked at. Anything Windows would run rather than open is shown in Explorer instead of started.

8. Being reachable: Windows Firewall

Dialling out from this PC always works. For another device to start a conversation with this PC, Windows Firewall has to let Kinzo through.

If it does not, a banner appears at the top of the window explaining what is wrong. Click Allow Kinzo, or go to Settings → Windows Firewall → Choose networks. Kinzo then asks which kinds of network to allow it on, and tells you which kind you are on now.

What Kinzo asks Windows for is deliberately narrow:

• Only Kinzo, not every program.
• Only its three ports, not all of them.
• Only from the local subnet — devices on your own network, never from the internet.

Changing this needs administrator approval, so Windows shows a prompt. Kinzo itself never runs as administrator; a small separate helper does that one job. You can remove the rules at any time from the same place.

Kinzo never changes your network’s category. Switching a network between public and private affects every program on the computer, and that is not Kinzo’s decision to make.

9. Staying reachable: the tray

Closing the window does not quit Kinzo — it keeps running by the clock, in the notification area. This is deliberate: a Kinzo that is not running cannot be reached at all, and to the phone this computer simply looks switched off.

• Double-click the tray icon to bring the window back.
• Right-click → Quit to actually stop it.
• Its tooltip shows how many unread messages you have.

To have Kinzo there after a restart, turn on Start Kinzo when I sign in in Settings. Only one copy of Kinzo runs at a time; starting it again brings the running window forward.

10. Settings

Open Settings with the gear at the top right.

11. Managing a conversation

Four buttons sit at the top right of an open conversation. Hover for what each one does:

Removing a device keeps the conversation

It stays open and readable. In place of the message box it says who ended it — “You removed name” or “name removed this device” — with a Pair again button, and the header says “Not paired”. If the device was off when you removed it, it is told the next time it connects. Messages it had not received yet are marked as not sent, and go out by themselves if you pair again.

When a device removes this computer, Kinzo tells you, with a notification if the window is not open.

12. Privacy & security

• Nothing leaves your network. No server, no account, no telemetry. Messages go straight from one device to the other.
• Every connection is encrypted with TLS, and both ends are authenticated.
• Keys are pinned at pairing. If something later claims to be a device you paired with but presents a different key, Kinzo refuses it. That is what stops another machine impersonating a device you trust.
• A saved address is a hint, not the device. If someone else answers at a paired device’s last address, Kinzo sends them nothing.
• Only paired devices can send you messages, files or a profile picture.
• Files and pictures that arrive are checked before being stored.

Everything is kept in %LOCALAPPDATA%\Kinzo on this computer:

13. When something is wrong

• “Other devices can’t reach this PC.” Windows Firewall is not letting Kinzo through on the network you are on. Settings → Windows Firewall → Choose networks.
• A device shows as connected on one side only. Usually the firewall, as above, on whichever side cannot be reached.
• A device never appears. See If nothing appears.
• Kinzo will not start, or says it is already running. Only one copy runs at a time. Look for it by the clock; starting it again brings that window forward.
• A photo shows as a grey tile. The file arrived but Windows has no codec for that format. Use Save as… and open it with something that can.
• Stickers show as grey squares, or the sticker picker is empty. Stickers are WebP pictures, and this computer is missing Microsoft’s free WebP Image Extensions. Install them from the Microsoft Store.
• “That device isn’t at its last address. Find it under Available.” The address Kinzo saved for that device now belongs to a different device, usually because you are on another network or the router handed the address out again. Kinzo will not send anything to the wrong device. Once the device is on this network it appears under Available; pair from there.
• A device you paired with is refused. Its key no longer matches the one pinned when you paired. That happens legitimately if Kinzo was reinstalled there. Remove the device on both sides and pair again.
• The phone and the PC still cannot see each other. The phone-side checklist — extenders, guest networks, client isolation — is in the Android guide’s troubleshooting.

14. Limits worth knowing

• Photos, videos and voice notes only, for the reason above.
• A device on a different subnet cannot start a conversation with this PC, because the firewall rules are limited to your local network. You can still start one from here.
• Emoji are black and white, and only the built-in sticker pack can be sent from this PC.
• Transfers do not resume. A file interrupted part-way is sent again from the beginning.
• Notifications are tray balloons rather than Windows toasts.