How do I duplicate a visual selection of lines in Vim?

Explanation

How it works

The :copy command (or its abbreviation :t) duplicates lines to a specified destination. When used with a visual selection range, it duplicates all selected lines.

The full command :'<,'>copy'> breaks down as:

• '<,'> - The visual selection range (auto-filled when you press : in visual mode)
• copy - The copy/duplicate command (also aliased as :t)
• '> - The destination: right after the last line of the selection

So you only need to type copy'> (or even shorter: t'>) after the auto-filled range.

Variations:

• :'<,'>t'> - Same thing using the shorter :t alias
• :'<,'>t0 - Copy selection to the top of the file
• :'<,'>t$ - Copy selection to the bottom of the file
• :'<,'>t42 - Copy selection below line 42
• :'<,'>t'<-1 - Copy selection above itself

This is much more efficient than y then p because it is a single command and does not alter any registers. Your yank register remains unchanged.

Example

Starting with this code:

def greet():
    print("hello")
    print("world")

1. Move to line 2, press V then j to select both print lines
2. Type :'<,'>t'> and press Enter

Result:

def greet():
    print("hello")
    print("world")
    print("hello")
    print("world")

The selected lines are duplicated immediately below without affecting your registers.