NeoServer is a powerful SSH client and server management tool for iOS (as well as iPadOS and macOS), hailed as an excellent alternative to PuTTY, Termux, and JuiceSSH. It supports terminal connections, SFTP file management, Docker/Podman container operations, real-time server monitoring (such as CPU, memory, disk, network, and GPU usage), and iOS widgets. It is worth mentioning that NeoServer natively supports the direct import of PuTTY private key format (.ppk), eliminating the need for additional conversion tools, which greatly simplifies the migration process from Windows PuTTY to iOS.

1. Preparation

• Download and Install NeoServer: Search for "NeoServer: SSH Client|Terminal" in the App Store to download and install (supports iPhone, iPad, and Mac). The free version includes basic SSH and SFTP features, while advanced features (such as certain SFTP edits, batch scripts, SOCKS5, etc.) require an in-app purchase to unlock.
• Get the .ppk file: Your PuTTY private key file (usually ending in .ppk). Ensure you know the username and Server IP/Domain corresponding to the key, as well as whether the key is password-protected.
• Server-side configuration: Ensure the remote server (Linux/NAS, etc.) has added the corresponding public key to the ~/.ssh/authorized_keys file and set the correct permissions (chmod 600 ~/.ssh/authorized_keys and chmod 700 ~/.ssh).

Note: NeoServer stores data locally and does not upload it to third-party servers. It supports iCloud sync and Face ID unlock, offering good privacy.

2. Directly Import .ppk Key into NeoServer

NeoServer has explicitly added support for the direct import of PuTTY private key format (.ppk) in version updates, and subsequent versions have fixed some key import issues.

Steps:

1. Open the NeoServer App.
2. Go to the Server Management or Host List interface (usually has a "+" button to add a server).
3. Click to add a new server/host and fill in the basic information:
   • Hostname or IP address
   • Port (default 22)
   • Username (the user corresponding to the key)
4. In Authentication Method, select Private Key or a similar option.
5. Click to import the key:
   • Supports importing from Files (Files App), Clipboard, or directly selecting the .ppk file.
   • Select your .ppk file; if the key is password-protected, the App will prompt you to enter the passphrase.
6. Save the server configuration.

After the import is successful, NeoServer will process the .ppk format and use it for SSH key authentication. You can click Connect to test directly.

Tips:

• If the import fails (a very small number of old version .ppk files), try updating the App to the latest version (8.0.4 and above have fixed some import issues).
• Supports Jump Host, SOCKS5 Proxy, suitable for enterprise intranets or complex network environments.
• Supports Wake-on-LAN (WOL), allowing you to wake up servers within the LAN.

3. If You Need to Convert .ppk (Optional, Not Required)

Although NeoServer supports direct import, if you want to use it in other tools or back it up, you can convert the .ppk to OpenSSH format (operating on a computer):

Using PuTTYgen on Windows:

1. Open PuTTYgen.
2. Click "Load" to load the .ppk file (requires entering the passphrase if there is one).
3. Menu "Conversions" → "Export OpenSSH key" to save as a private key file (e.g., id_rsa).
4. The public key part can be directly copied for use in the server's authorized_keys.

Using puttygen on Linux/macOS (requires installing putty-tools):

puttygen yourkey.ppk -O private-openssh -o id_rsa
puttygen yourkey.ppk -O public-openssh -o id_rsa.pub

After conversion, you can also import the OpenSSH format private key into NeoServer (the App usually also supports standard OpenSSH private keys).

4. Connection and Usage

• After adding the server, click Connect in the host list.
• NeoServer's terminal supports:
  • Copy/Paste
  • Special keyboard (arrow keys, Ctrl, etc.)
  • tmux session recovery
  • Shell script initialization
  • Command auto-completion (triggered by double-tapping TAB)
• It also supports SFTP browsing, editing, and uploading/downloading files (free version supports basic operations).
• Server monitoring: Real-time viewing of CPU temperature, GPU usage, disk IOPS, network speed, etc., and you can add iOS 17 widgets.

Advanced Features (Premium):

• Custom terminal themes
• Batch server script execution
• Full SFTP file editing (syntax highlighting)
• Container creation/restart and other operations

5. Troubleshooting

• Key Authentication Failed: Confirm that the server-side public key is correct and permissions are set correctly; check if the .ppk has a password and enter it correctly; try restarting the App or device.
• Import Error Prompt: Update the App, or try exporting to OpenSSH format using PuTTYgen first and then importing.
• Network Issues: Use Jump Host or SOCKS5 proxy to solve intranet access.
• Multi-device Sync: Enable iCloud sync, and keys and server configurations can be shared between iPhone/iPad/Mac.

6. Why Recommend NeoServer?

• Designed specifically for server management, far surpassing simple terminal tools.
• Particularly friendly for NAS (such as Synology, TrueNAS, QNAP), self-hosting, and Docker users.
• Modern interface, supports Dark Mode, and has strong visualization for monitoring.
• Developer feedback channel: [email protected] (also available within the App).

Through NeoServer, you can easily and securely manage remote servers using PuTTY's .ppk keys on your iPhone or iPad, without the need for extra conversion, ensuring smooth operation. If you are moving from Windows PuTTY to iOS, this is one of the best choices.