How to Use PuTTY for SSH on Windows (and Whether You Still Need It)

Q: How do I use an SSH key with PuTTY?

PuTTY uses `.ppk` keys. Generate or convert one with PuTTYgen, then point PuTTY at it under Connection > SSH > Auth > Credentials, and put the matching public key in the server's `~/.ssh/authorized_keys`. Loading the key into Pageant, PuTTY's agent, makes every session offer it automatically.

To SSH with PuTTY, download it, enter your server’s hostname or IP and port 22, click Open, and log in - that is the whole basic flow. Save the session so you do not retype the details, and for key-based login point PuTTY at your private key (a .ppk file) or load it into Pageant. But the honest first question in 2026 is whether you need PuTTY at all: Windows 10 and 11 now ship a built-in OpenSSH client, so ssh user@host works from PowerShell or Terminal with no install. PuTTY is still excellent, especially for saved sessions and key management - just know it is now a choice, not a requirement.

PuTTY was the way to SSH from Windows for two decades. It still works beautifully. It is also no longer the only option built into the OS, which changes when it is worth reaching for.

The basic connection
Saving a session so you stop retyping
Key-based login with PuTTY and Pageant
The tools that come with PuTTY
Do you still need PuTTY in 2026?
How this fits the rest of the stack
FAQ

The basic connection

Download PuTTY from the official site (putty.org links to the real one - be wary of imitations that bundle junk), install or run the standalone exe, and open it.

In the configuration window:

Host Name (or IP address) - your server’s address, for example [email protected] or just the IP.
Port - 22 unless your server uses a custom SSH port.
Connection type - SSH (the default).
Click Open.

The first time you connect to a host, PuTTY shows a security alert with the server’s key fingerprint. This is normal - it is asking you to confirm the server’s identity. Accept it and the fingerprint is cached, so you are only warned again if it changes (which could mean a real problem). Then log in with your username and password, or your key.

Saving a session so you stop retyping

Typing the host every time gets old fast. Save the session:

Enter the Host Name and Port as above.
In the Saved Sessions box, type a name (for example prod-web).
Click Save.

Now that server is one double-click away in the session list. You can save all the connection settings per session - the key to use, the username under Connection > Data > Auto-login username, terminal preferences, tunnels. For anyone managing several servers, saved sessions are the main reason to keep using PuTTY: a labelled list of connections, each pre-configured, beats remembering IPs and flags. Set up each server once and never type its details again.

Passwords are fine for a first connection; keys are what you should use for anything real. PuTTY uses its own key format, .ppk:

Generate or convert a key with PuTTYgen (ships with PuTTY). Generate a new Ed25519 or RSA key, or Load an existing OpenSSH key and Save it as .ppk.
Point PuTTY at it: Connection > SSH > Auth > Credentials > Private key file.
Put the public key on the server in ~/.ssh/authorized_keys for your user.

Better still, run Pageant, PuTTY’s key agent. Add your .ppk to Pageant once, and every PuTTY session offers it automatically - no per-session key selection, and you unlock the key a single time. If you ever hit No supported authentication methods available (server sent: publickey), it almost always means the key was not loaded here.

The tools that come with PuTTY

PuTTY is not just the terminal window - the package includes command-line tools worth knowing:

PuTTYgen - generate and convert SSH keys, and change their passphrases.
Pageant - the key agent that holds your loaded keys.
pscp - secure copy files to and from a server (pscp file.txt user@host:/path).
psftp - an interactive SFTP client for file transfer.
plink - PuTTY’s link tool for scripting SSH commands and building tunnels.

So if you have PuTTY, you already have file transfer and scripting, not only interactive login. pscp and psftp cover moving files without a separate tool, and plink lets you run remote commands from a batch script or set up port forwards. For a Windows shop standardised on PuTTY, that suite handles most SSH-adjacent tasks.

Do you still need PuTTY in 2026?

Windows 10 and 11 ship a built-in OpenSSH client. From PowerShell or Windows Terminal:

ssh user@host
scp file.txt user@host:/path

No install, standard OpenSSH keys in %USERPROFILE%\.ssh, and the same commands you would use on Linux or macOS. For a quick connection, this is often the faster path - nothing to download, and your ~/.ssh/config works the way it does everywhere else.

So PuTTY is now a choice:

Reach for built-in OpenSSH for one-off connections, or if you already live in a Unix-style SSH workflow and want consistency across machines.
Reach for PuTTY if you value its saved-session manager, prefer a GUI for keys and tunnels, or manage many servers and want them all in a labelled list.

Neither is wrong. PuTTY is not obsolete - it just stopped being mandatory, and knowing both means you use whichever fits the moment.

How this fits the rest of the stack

Whatever you decide here, the cost of it eventually shows up as a bill. The RunxBuild hosting calculator is the right place to model that before committing: the compute, the database, the storage, the bandwidth, the worker - each one is a separate line item, and the real cost of a platform is the sum, not the headline number. The RunxBuild dashboard is where the team sees the actual usage once it is running.

Useful related references:

FAQ

How do I use PuTTY to SSH into a server?

Download PuTTY, open it, enter your server’s hostname or IP and port 22, keep the connection type as SSH, and click Open. Accept the host key fingerprint on first connection, then log in with your username and password or key. Save the session to avoid retyping the details next time.

How do I save a session in PuTTY?

Enter the host name and port, type a name in the Saved Sessions box (for example prod-web), and click Save. The server then appears in the session list and is one double-click away, with all its settings - key, username, terminal preferences - stored. Saved sessions are a main reason to keep using PuTTY for multiple servers.

How do I use an SSH key with PuTTY?

PuTTY uses .ppk keys. Generate or convert one with PuTTYgen, then point PuTTY at it under Connection > SSH > Auth > Credentials, and put the matching public key in the server’s ~/.ssh/authorized_keys. Loading the key into Pageant, PuTTY’s agent, makes every session offer it automatically.

Do I still need PuTTY on Windows 10 or 11?

Not necessarily - Windows 10 and 11 include a built-in OpenSSH client, so ssh user@host works from PowerShell or Terminal with no install and standard OpenSSH keys. PuTTY is still excellent for saved-session management, GUI key handling, and tunnels, but it is now a choice rather than a requirement.

What tools come with PuTTY?

Besides the terminal, PuTTY includes PuTTYgen (key generation and conversion), Pageant (key agent), pscp and psftp (file transfer), and plink (scripting SSH commands and tunnels). So installing PuTTY gives you secure file copy and command scripting, not just interactive login.