How do I insert a blank line above or below the current line without entering insert mode?

Explanation

Using :put ='' with an empty expression lets you insert blank lines in normal mode without ever entering insert mode. This is especially useful in mappings, since it avoids the state-change side effects of o or O, and it preserves the current register contents.

How it works

• :put pastes the result of a register or expression after the current line (like p)
• :put! pastes before the current line (like P)
• ='' uses the expression register and evaluates to an empty string, which Vim inserts as a blank line
• Unlike o or O, the cursor ends up on the new blank line but normal mode is preserved

Example

Before (cursor on line 2):
  line 1
  line 2       ← cursor here
  line 3

:put =''   → inserts blank line after:
  line 1
  line 2
               ← new blank line
  line 3

:put! =''  → inserts blank line before:
  line 1
               ← new blank line
  line 2
  line 3

Tips

• Map these to convenient keys: nnoremap <leader>o :put =''<CR> and nnoremap <leader>O :put! =''<CR>
• Useful in scripts and autocommands where you need to add spacing without changing mode
• The expression register = is powerful here — you can insert any computed value: :put =repeat('-', 80) inserts a line of 80 dashes
• Combine with a range: :5put ='' inserts a blank line after line 5 regardless of cursor position