Why doesn't \n insert a newline in a :s replacement, and what should I use instead?

Explanation

In Vim substitutions, \n and \r behave differently depending on whether they appear in the search pattern or the replacement string — a common gotcha that surprises even experienced users.

How it works

In the search pattern:

• \n — matches a newline (end of line)
• \r — matches a carriage return (\r, ASCII 13)

In the replacement string:

• \r — inserts a real newline (splits the line)
• \n — inserts a null byte (not a newline!)

So to split a line at a delimiter, use \r, not \n, in the replacement.

Example

Given a comma-separated line:

apple,banana,cherry

Running :%s/,/,\r/g splits it into multiple lines:

apple,
banana,
cherry

Using :%s/,/,\n/g instead inserts null bytes — the file appears unchanged or corrupted.

Conversely, to search for and remove newlines between lines, use \n in the search side:

:%s/\n/ /g

This joins all lines into one by replacing each newline with a space.

Tips

• Remember: \r in replacement = newline, \n in search = newline — they're on opposite sides
• To join lines without a separator: :%s/\n//g
• In very magic mode (\v), the same rule applies: \r in replacement, \n in pattern