How to fix copy and paste behavior in PuTTY

Copy and paste problems in PuTTY usually appear as accidental pastes on right-click, selected text not ending up in the Windows clipboard, or mouse selection stopping inside full-screen terminal programs. Fixing the selection settings prevents unintended command execution and makes it easier to move commands, paths, and logs between the terminal and other applications.

On Windows, PuTTY uses an xterm-style selection model where dragging with the left mouse button selects text and paste is triggered by a configurable mouse button or a keyboard action such as Shift+Insert. Common desktop shortcuts can have a different meaning in terminal sessions, so PuTTY keeps terminal copy/paste separate from server-side control keys.

Copy/paste behavior is stored per saved session (including Default Settings), and changes only apply to new windows unless applied via Change Settings in an existing session. Some terminal applications enable mouse reporting, which redirects mouse clicks to the remote program, and pasting multi-line or untrusted text can include newlines and control characters with surprising effects.

1. Launch PuTTY.
2. Select the saved session to update and click Load.

   Select Default Settings to apply the changes to new sessions by default.

3. Expand Window and select Selection in the category tree.
4. Select Windows in Action of mouse buttons.

   Compromise pastes on right-click, Windows shows a context menu, and xterm pastes on middle-click.
   Ctrl+Right-click always opens the context menu.

5. Enable Auto-copy selected text to system clipboard.

   Ctrl+C sends an interrupt to the remote session and can stop a running command.

6. Ensure Shift overrides application's use of mouse is enabled.

   Hold Shift while selecting text when a terminal program captures the mouse (for example mc).

7. Keep Permit control characters in pasted text disabled.

   Enabling this can paste hidden control characters (for example ESC) into the session.

8. Return to Session and click Save.
9. Click Open to start a new session with the updated settings.

   Apply the same options to an existing window by selecting Change Settings from the window menu.

10. Drag with the left mouse button to select a line of output in the terminal window.

    Releasing the mouse button copies the selection to the Windows clipboard when Auto-copy selected text to system clipboard is enabled.

11. Paste into Notepad using Ctrl+V.
12. Copy a short test string in Notepad using Ctrl+C.
13. Select Paste from the PuTTY right-click context menu.

    Paste is sent at the text cursor, not at the mouse pointer, so move the cursor before pasting.
    Shift+Insert pastes from the clipboard even when right-click is configured for the menu.