Text
Remove empty lines
Flags: gm
Strip blank lines (lines containing only whitespace) from a block of text.
Pattern
Regular expression
^\s*$\r?\nHow it works
The `m` flag makes `^` and `$` match line boundaries. `\s*` allows the line to contain any whitespace, and `\r?\n` consumes the trailing newline (both LF and CRLF).
Matches
- ▸`\n\n` (double newline)
- ▸` \n` (whitespace-only line)
Non-matches
- ▸`text\n` (has content)
Language snippets
JavaScript
text.replace(/^\s*$\r?\n/gm, "");Python
re.sub(r"^\s*$\r?\n", "", text, flags=re.M)Go
re := regexp.MustCompile(`(?m)^\s*$\r?\n`)
re.ReplaceAllString(text, "")Java
text.replaceAll("(?m)^\\s*$\\r?\\n", "")Frequently asked questions
What is the regex for Remove empty lines?
The pattern ^\s*$\r?\n (flags: gm) matches Remove empty lines. The `m` flag makes `^` and `$` match line boundaries. `\s*` allows the line to contain any whitespace, and `\r?\n` consumes the trailing newline (both LF and CRLF).
What does this Remove empty lines pattern match?
It matches strings like `\n\n` (double newline), ` \n` (whitespace-only line), but rejects `text\n` (has content).
How do I use this pattern in JavaScript, Python, Go, Java?
Ready-to-run snippets are provided for JavaScript, Python, Go, Java. Copy the one for your language from the Language snippets section — each wraps the same core pattern in that language's regex API.