Regex for Whitespace (multiple/leading/trailing)
Match runs of whitespace for trimming or collapsing.
The Whitespace (multiple/leading/trailing) regex is \s+ — copy it below, or open it in the explainer for a token-by-token breakdown.
The pattern
What it matches
spaces between
What it doesn't match
no-space
Notes & gotchas
Use with replace: str.replace(/\s+/g, " ").trim() collapses multiple spaces and trims. Includes spaces, tabs, newlines, carriage returns.
Code in your language
Use the explainer's Code tab to generate ready-to-paste snippets in JavaScript, Python, Java, .NET, Go, Ruby, and PHP for this pattern.
Open in explainer →Token-by-token breakdown
Every part of the pattern, left to right:
| Token | Meaning |
|---|---|
\s+ | one or more: whitespace |
About this pattern
Number patterns appear constantly in form validation, log parsing, and data extraction. Regex is great for matching the shape but limited for semantic checks (range validation, mathematical constraints).
Quick usage in different languages
This exact pattern — with the correct escaping and idioms for each language:
- JavaScript:
/\s+/.test(value) - Python:
re.match(r"\s+", value) - Java:
Pattern.compile("\\s+").matcher(value).matches() - C# / .NET:
Regex.IsMatch(value, @"\s+") - Go:
regexp.MustCompile(`\s+`).MatchString(value) - Ruby:
/\s+/.match?(value) - PHP:
preg_match('~\s+~', $value)
The explainer’s Code tab regenerates these for any pattern you paste, and the downloadable cheat sheet bundles the breakdown, all seven snippets, and the pitfalls below onto one printable page.
Common pitfalls
- Not anchored. Without ^ and $ this can match a substring anywhere in the input — add anchors if you need the whole value to conform.
- Escape it correctly per language. In Java and JavaScript strings each backslash must be doubled (\\d); in Python, Go, and C# use raw/verbatim strings so the backslashes survive.
- Validate beyond format. Matching the format doesn't guarantee the value is real. Confirm the whitespace (multiple/leading/trailing) against a source of truth (database, API, or checksum) where it matters.
Related patterns
More patterns in the Numbers & text category:
See also
Browse all 300 patterns in the library, or open this regex in the interactive explainer for a token-by-token breakdown, live testing, and code in seven languages.
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