How do I apply ROT13 encoding to the current line in Vim without using a motion or visual selection?

Explanation

Vim has a built-in ROT13 operator g? that encodes text by rotating each letter 13 positions in the alphabet. Like other operators, doubling it — g?? — applies it to the entire current line, without needing to specify a motion or enter visual mode first.

How it works

• g?{motion} — ROT13 the text covered by {motion}
• g?? — ROT13 the current line (line-wise, like dd or gqq)
• Applying ROT13 twice restores the original text (it is its own inverse)
• All non-alphabetic characters (numbers, punctuation, spaces) are left unchanged

Example

With the cursor on this line:

Hello, World!

Press g??:

Uryyb, Jbeyq!

Press g?? again to decode:

Hello, World!

Tips

• g?iw ROT13 encodes just the current word
• g?ip encodes the entire inner paragraph
• In visual mode, select text then press g? to encode the selection
• Useful for obfuscating spoilers, test data, or example output in documentation
• Combine with :g/pattern/norm g?? to encode all matching lines in one command