Frequently asked questions.

Zynk lets you send files between your phone, computer, and other devices, share files with other people, and send messages. Direct file transfers have no size limit and are end-to-end encrypted.

The answers below explain how it works. If you have another question, get in touch.

• •App: Windows, macOS, Linux, iOS, Android (including TV), and Steam Deck
• •CLI: Windows, macOS, Linux (including Raspberry Pi), and FreeBSD

Yes. You sign up with your email address, and every device you sign in on becomes part of the same account. If you created your account back when Zynk used phone numbers, your number still signs you in, but new accounts are email-only.

An account is what makes Zynk effortless long term. Your devices and contacts stay with you, so you never re-pair machines or dig up a fresh link for someone you've already sent to.

Download the app, run it and follow instructions. You'll be done in less than a minute.

Yes. Pick a username in the app, like @dana, and give people that instead. Anyone who adds you by username can send you files and messages, and your email address and phone number stay private.

You still sign in with the email address or phone number on your account, and you can change or drop your username whenever you like.

Yes. Zynk is free and ad-free, and every feature is available to everyone. There are no paid plans.

• •

  App: A classic, graphical and user-friendly interface for everyday use, available on your phone, tablet, computer and even some TVs.

• •

  CLI: Runs in your terminal, ideal for scripting, automation, power users, as well direct, server to server data transfer. Runs on all major operating systems.

On the new device, select Link device, then scan the QR code or enter the 6-digit code when prompted.

Open Devices → Remove/Unlink. The device's authorization is revoked until you add it again.

There's no hardcoded limit; multiple devices per account are supported.

One active account per app/instance. You can sign out and link a different account, but running multiple accounts on the same device at the same time isn't supported.

No. Each device profile is tied to a single account. Use separate profiles or sign out/in between accounts.

Yes!

• •

  Use Web Share to create instant download links for files and folders you want to share with anyone.

• •

  Use Web Drop to create an upload link so anyone can send files to you from their browser—no app required.

These are powerful features that work without requiring the other person to install Zynk:

• •

  Web Share: Upload files and folders to create an instant, browser-based download gallery. Perfect for sharing work, photos, or documents with anyone via a simple link.

• •

  Web Drop: Create a personalized upload link where others can send files to you from their browser. You set the size limit. Great for collecting files from clients, team members, or friends without them needing an account.

Among its many capabilities Zynk allows you to transfer files and folders between devices and different Zynk users who are also on the same network, at network speed.

Max out your WiFi when transferring files. These transfers should work, in most circumstancs, even when Internet access is not available.

Zynk works everywhere, be it on a local home or company network, or through the Internet.

• •

  Direct transfers between devices or people: No size limit. Transfers auto-resume if connection drops.

• •

  Web Share and Web Drop: Uploads are stored in the cloud, so they count toward your account's web storage. For Web Drop, you set the size limit when creating the upload link.

• •

  Files stay unchanged: Zynk transfers files exactly as they are, no compression or modification

• •

  CLI: Saves to the folder you choose (default: current directory).

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  App: Saves to the storage folder you set, or the default downloads folder of your device if you did not change the setting.

There's no dedicated block/report feature. You control who you authorize, can ignore requests, and can remove devices at any time.

For abuse or issues, contact us through the app's built in feedback feature, or through the contact form on the site.

No ads. We use crash reports to improve stability and push notifications for delivery. Push payloads are encrypted end-to-end to your device keys, nobody can read them but you, not even us.

Zynk always first attempts to establish direct connectivity between users and devices (on LAN or over the Internet). If that's blocked by the network, Zynk uses encrypted relay servers as a fallback so your transfer still works, while maintaining end-to-end encryption.

As secure as they can be, and probably more secure than most messaging or competing apps, since data flows directly between devices/users (P2P) and that is combined with the fact that data is always End to End encrypted (E2EE).

We made sure to keep data we need to the bare minimum required to safely operate the service.

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  On your devices: Contacts, device list, transfer history, and settings.

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  On the server for web links: Counts, sizes, and expiry to enforce your quota and the actual content, so we are able to deliver it.

We don't run any ads or sell your data. Push notifications include encrypted payloads we can't read.

No, device-to-device transfers and messages are end-to-end encrypted.

Your account is tied to your email address (or, on older accounts, a phone number). A username is just an extra way for people to find you. Each device has its own unique cryptographic key. Linking via QR or a 6-digit code verifies the new device before it's added to your account. That's an action only you can approve.

All links use HTTPS encryption and expire automatically. Optional password protection is available for added security.

Uploads count towards your account's web storage.

Currently not.

You can close your account from Settings. Logging out only removes local data on that device but keeps basic account information on our servers. A self-serve "export my data" option isn't available, and anyway there's nothing of use that we store beyond the bare minimum.

If you are experiencing connection problems, please ensure that your firewall or antivirus software is not blocking Zynk. You can also try restarting your router or switching to a different network.

Note that network and speed issues are generally transient, and generally happen somewhere on the Internet, between your device, and your peer.

To diagnose some of the issues you can use the built in speed-test function inside Zynk, you can find it in the settings.

If the issue persists, please contact us at https://zynk.it/contact with details about your setup and the problem you are facing.

Possibly. We have no way of knowing how they might affect Zynk because every network is different, but generally adding VPN services causes your traffic to be rerouted through another server, which can affect performance.

Due to iOS restrictions, Zynk needs to be open in the foreground, and the device screen must be on in order to send or receive files. This is a limitation imposed by Apple on third-party apps. We recommend keeping the app open and the screen for the entire duration of a transfer for the best experience.

This may not affect other apps on iPhone or iOS because they generally transfer lower quality media files, which are in most cases significantly smaller so it takes less time to send them to a server.

Port 443 is used, both TCP and UDP. Generally you don't need to make any changes to your firewall settings.

Windows

• •Windows Terminal + PowerShell 7 (pwsh) for tabs, GPU rendering, and good defaults
• •Optional: VS Code's integrated terminal if you mostly work inside VS Code

macOS, Linux, FreeBSD

• •Ghostty
• •WezTerm
• •kitty

Terminals support different color depths. If yours is limited to 256 colors (or less), themes look flatter.

You can disable color with --no-color or try a modern terminal (WezTerm, kitty, Ghostty).

Use your OS's standard config directory. Run zynk show-default-config-path to see the exact location.

Pipe file lists into zynk send, for example:

fd '*.pdf' | zynk send "Jesse James"

Set a default receive folder with setdownloadpath, and enable unattended receives with autoaccept.

• •🇺🇸 English (US)
• •🇩🇪 German (DE)
• •🇮🇹 Italian (IT)
• •🇮🇳 Hindi (IN)
• •🇳🇵 Nepali (NP)

Want to see Zynk in your own language? Help us translate it! Get in touch and we'll share the contributor guide.

We are committed to making Zynk accessible to all users. We support system-wide accessibility features such as VoiceOver, Dynamic Type, and Dark Mode on iOS and macOS. If you have specific accessibility needs or suggestions, please contact us at https://zynk.it/contact

• •Privacy Policy: zynk.it/privacy-policy
• •Terms and other legal pages: See zynk.it

Use Send Feedback in the app's settings, or the CLI command feedback "...".

Inside the app's settings via the Bug Report option, or the CLI command bugreport "...", or report via our website at zynk.it.

We primarly use e-mail support. If you have questions or need help, please contact us at our contact page: https://zynk.it/contact

Oh you found the hidden capybaras? congratulations! We love them! They are amazynk!