Replace6 chars · /g
Regex to Collapse Blank Lines
Helpful when normalizing pasted docs, generated markdown, or support transcripts with too much vertical space.
The expression
/\n{3,}/gHow to read it
A brace quantifier fixes how many times the previous token repeats.
g — global — keep going after the first match instead of stopping
Find matches in your own text
no inputTry:
This expression is unanchored, so it finds every occurrence anywhere in the text. Highlighted runs are what a replace call would rewrite.
Examples, checked in your browser
4/4 verifiedline1 line2
Matches.
a b
Matches.
line1 line2
No match — this is the kind of input the pattern rejects.
single line
No match — this is the kind of input the pattern rejects.
Use it in code
3 languagesJavaScript
const regex = /\n{3,}/g;
regex.test(input);Python
import re
pattern = re.compile(r"\n{3,}")
bool(pattern.search(input))Go
re := regexp.MustCompile("\\n{3,}")
matched := re.MatchString(input)Other replace patterns
3GroupReplace
Flags/g
Examples4
SafetyOK