SubmarineTerminal
Tabs, split view, true colour, 10,000 lines of scrollback, colour schemes and Nerd Fonts. Search what it shows with Ctrl+Shift+F, and the commands you typed with Ctrl+Shift+R.
0.4Remote desktops with a shared clipboard and speed choices
All your servers in one encrypted app
Submarine is an SSH, SFTP, RDP, VNC and Telnet client for Windows, macOS, Linux and Android. Your servers, passwords and keys are encrypted on your device, and they sync between your devices only if you want them to.
- No ads
- No tracking
- No paid plan
- No account needed
WindowsmacOSLinuxAndroid
One app instead of
a terminalan SFTP clienta tunnel manageran RDP appa VNC viewera Telnet clientSubmarine
Features
Everything for your servers, in one window
Connect, transfer, forward, watch and share, on every computer you use and on your phone.
The Wall
Many servers side by side, and typing into all of them at once.
Two-pane SFTP
Drag and drop, compare folders, edit remote files, archives, sudo, and servers without SFTP.
RDP and VNCNew in 0.4
Remote desktops in a tab, with a shared clipboard, speed and quality choices, and a mark that shows how the link is doing.
TelnetNew in 0.4
For old switches and routers, clearly marked as not encrypted.
Tunnels
Local, remote and SOCKS forwarding, with a live log of every connection.
Keys and agentsNew in 0.4
Your ~/.ssh/config, SSH agents, hardware keys, OpenSSH certificates, jump hosts and proxies.
Encrypted profile
AES-256-GCM with an Argon2id key. Unlock it with Windows Hello or your fingerprint, if you like.
Sync, if you want it
Between your devices, each item encrypted on the device before it is sent.
Shared profiles
Share servers with your team. Each member gets the profile's key sealed to them.
Monitoring
CPU, memory, disk and network, an alert when a server goes down, services and Docker.
Commands and notes
Keep the commands you run often and paste or run them in a terminal.
Android
The same profile on your phone, with a key bar for the terminal.
Imports
Bring your servers over from PuTTY, MobaXterm and OpenSSH.
A closer look
Made for the work you do every day
A terminal that keeps up
Tabs, split view and the Wall, which shows many servers side by side and can type into all of them at once.
- Search what the terminal shows with Ctrl+Shift+F, and the commands you typed with Ctrl+Shift+R (Cmd+Shift on a Mac). Plain Ctrl+F and Ctrl+R stay with the shell.
- Right-click the + button for a terminal with its own login, on a connection of its own: once, or always for that server.
- True colour, 10,000 lines of scrollback, colour schemes and Nerd Fonts.
Files, side by side
Two-pane SFTP with drag and drop between your computer and the server.
- Compare two folders: files that differ, are newer or exist on one side only are marked.
- Edit remote files live, and pack and unpack archives on the server.
- Work as root through sudo, even on servers without SFTP.
- Mirror a local folder to a server as you change it (on a computer).
Tunnels without the command line
Local, remote and SOCKS forwarding with names, started together with the app if you like.
- A live log of every connection that goes through a tunnel.
- Through jump hosts and proxies, like any other connection.
Works with what you already have
Reads your ~/.ssh/config and imports from PuTTY, MobaXterm and OpenSSH.
- Uses your SSH agent: Pageant, the Windows OpenSSH agent, 1Password, hardware keys.
- OpenSSH certificates, jump hosts, and HTTP and SOCKS proxies.
- When a saved password is wrong, or none is saved, the password prompt offers Save password. It is kept once the login works.
Know when something breaks
Watches CPU, memory, disk and network over SSH and tells you when a server goes down.
- Nothing to install on the server.
- Server info, services and Docker containers in one place.
Your logins, locked
Passwords and keys live in an encrypted profile that only your password opens.
- AES-256-GCM, with a key made from your password by Argon2id. The password is never stored.
- Unlock with Windows Hello, or with your fingerprint on Android. Off until you turn it on.
- Locking the profile closes every connection, even one that is still logging in.
On your phone as well
The same profile on Android, with the same encryption.
- A terminal with a key bar for Ctrl, Alt, Esc, Tab and the arrows.
- File transfer and tunnels.
- Remote desktops with touch, zoom, the shared clipboard, the connection mark and the speed choices. A phone shares no files with an RDP server.
New in 0.4
Remote desktops, right next to your terminals
VNC and the built-in RDP client open in a tab, directly or through one of your SSH servers. RDP can also open in your computer's own RDP app.
See how the link is doing
A mark in the tab says Good, Fair, Weak or Not answering, with the delay. Its panel shows how much data goes each way, and on a weak link it offers to use less data.
A sharp picture, or less data
Choose the colours, the resolution and, for VNC, how often the picture is updated, or pick a quick choice such as Less data. A hidden tab pauses its picture, so nothing is sent while nobody is looking.
A shared clipboard
Text you copy on the remote desktop comes to your clipboard, and yours goes there only when you paste. VNC carries plain text only.
Shared files over RDP
The built-in RDP client can share a folder or a whole drive, read only if you like. On a computer, not on a phone. The choice stays on this device and is never synced.
Your RDP app, without typing the password
Through an SSH server, your RDP app connects to the same local address every time, so what it remembers (a trusted certificate, a saved login) is found again. On Windows, Remote Desktop Connection also gets the saved password, encrypted, in a file that is deleted once it is read.
Through your SSH servers
RDP, VNC and Telnet can all go through one of your SSH servers. Connections that are not encrypted are clearly marked.
The built-in RDP client is experimental, and off until you choose it for a server (Open in: Submarine's tab). Until then, RDP opens in your computer's RDP app. On Android, the built-in client is the one used.
Private by design
Your data is yours. We can't read it.
Your data is encrypted before it is saved, and before it leaves your device. We publish exactly what our server can and cannot see.
Encrypted on your device
Profiles are encrypted with AES-256-GCM. The key is made from your password with Argon2id. The password itself is never stored or sent.
Sync is optional
If you turn it on, every item is encrypted on your device first. The server keeps only the encrypted version. It does see some details around it, such as your email address and when you sync, and we list them all.
No tracking
No ads, no analytics, no crash reports. The app talks only to your servers, to the sync server if you sign in, and to GitHub to check for a new version.
Free
Free. Really.
No paid plan, no trial, no ads, and no account needed.
- Submarine is free and open source under the MIT license.
- You don't need an account. An account is only for the optional sync between your devices.
- The sync service is free as well, within fair limits: 5 MB of encrypted data, 20,000 items and 100 profiles per account.
- The source code is public. You can read it, build the app yourself, or use a sync server of your own.
Download
Get Submarine
All downloads come from the project's releases on GitHub.
This page describes version 0.4, which is in its last tests and not released yet. Until it is, the Download buttons give version 0.3.8. Version 0.3.8 has the terminal, file transfer, tunnels, monitoring and sync, but not the remote desktops, Telnet, Windows Hello and fingerprint unlock, SSH agents, folder compare and the rest of what 0.4 adds. From 0.4, Windows also gets a portable .zip.
Check your download
- From version 0.4, every release has a SHA256SUMS file with the checksum of each download.
- From version 0.4, the Android app is signed with the author's key. Its certificate's SHA-256 fingerprint is
e9e350dc9f8628bee461be3424c0c2b2180f00685cc380de80c86808ae669f1c. - The Windows and macOS builds are not code-signed yet, so your system may warn you the first time you open them.
Help
Questions and answers
Is Submarine really free?
Yes. The app is free and open source under the MIT license, with no paid plan and no ads. The sync service is free too, within the limits above.
Do I need an account?
No. Everything works without one. You only need an account if you want to sync profiles between your devices.
Can the sync server read my passwords?
No. Every item is encrypted on your device before it is uploaded, and the server never gets the key. It does see some details around your data, such as your email address, when you sync, and how many items you have. The security page lists all of them.
What if I forget my profile password?
Then nobody can open that profile, not even us. There is no recovery, because the password is never stored anywhere. Keep it somewhere safe.
Can I use RDP, VNC and Telnet?
Yes, from version 0.4. VNC shows the screen in a tab and shares the clipboard (plain text). RDP opens in your computer's RDP app, or in a tab with the experimental built-in client, which shares the clipboard and, on a computer, a folder or a drive. In a Submarine tab, both show how the connection is doing and let you trade picture quality for less data. Telnet opens in a terminal tab. All three can go through an SSH server, and Telnet and plain VNC are marked as not encrypted.
What does a remote desktop get from my computer?
Clipboard text when you paste into its tab, and nothing before that. Text copied on the server comes to your clipboard while Share the clipboard is on. Files only if you choose a folder or a drive for the built-in RDP client, on a computer. These choices are kept on your device and never synced, so nobody you share a profile with can turn them on.
Which systems does it run on?
Windows 10 and 11, macOS on Apple Silicon (M1 and later), Linux (.deb, .rpm, Arch, AppImage) and Android 7.0 or later.
Can I use my own sync server?
Yes. In the app, open Cloud sync and change the sync server. Our server's code is not published, so a server of your own has to offer the same API, which is described in the app's source code.
How do I delete my account?
In the app (version 0.4 and later), use Delete account… in Cloud sync. You can also do it on the delete account page.