PuTTY prompts for a username when starting an SSH session, which slows down repetitive connections and makes it easier to authenticate as the wrong account. Saving a default username in a session profile streamlines logins to the same server or role account.
PuTTY stores connection options as a session profile, including the Auto-login username field under Connection → Data. When the session opens, PuTTY sends that username during the SSH authentication handshake before continuing with password, key-based, or keyboard-interactive prompts.
The auto-login username is not a credential and does not store a password. The setting applies per saved session unless saved as Default Settings, and an incorrect username can cause repeated authentication failures that may trigger lockouts or IP bans on hardened servers.
Steps to set a default username in PuTTY:
- Launch PuTTY.
- Enter the SSH server Host Name (or IP address) under Session.
- Set the SSH server Port under Session.
- Select an existing session under Saved Sessions.
Skip when configuring a new session from scratch.
- Click Load.
- Select Connection → Data in the category tree.
- Enter the username in Auto-login username.
Auto-login username stores only the username and does not save a password.
Wrong usernames can trigger authentication failures and may trip account lockouts or IP bans on hardened SSH servers.
- Select Session in the category tree.
- Type the session name in Saved Sessions.
Saving as Default Settings applies the username to new sessions created later.
- Click Save.
Saving to an existing session name overwrites its previous settings.
- Click Open.
- Open the PuTTY system menu (top-left icon).
- Select Event Log.
- Confirm the Using username entry matches the configured username.
Mohd Shakir Zakaria is a cloud architect with deep roots in software development and open-source advocacy. Certified in AWS, Red Hat, VMware, ITIL, and Linux, he specializes in designing and managing robust cloud and on-premises infrastructures.
