Find Horizontal Whitespace Runs

Find runs of spaces and tabs without matching line breaks.

Checking engine…

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Workspace actions
Regular expression
Reference

Regex quick reference

^ · $
Start/end; m = lines.
[abc] · \d
Listed character / digit.
* · + · ?
Zero or more, one or more, optional.
(...)
Capture a numbered group.
(?<name>...)
Named capture.
(?=...)
Ahead; lookbehind varies.
i · m · s
Ignore case / line anchors / dot-newline.
Browse the full reference

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the RegExp of this browser (version not pinned)

Not available in JavaScript · This browser: x · ignore pattern whitespace; a · ASCII-only classes; U · lazy by default; J · duplicate names. u and v cannot be combined.

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Test text

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Verified Fixture FX-R11

What it does

Find runs of spaces and tabs without touching line breaks.

How to use it

  1. Load the example or paste your text.
  2. Check the matches.
  3. Replace them on the Replace page if needed.

Verified example

Example

Text "a b\tc"

JavaScript · This browser
[ \t]+

Result: " ", "\t"

Python re · Local WASM
[ \t]+

Result: " ", "\t"

PCRE2-8 · Local WASM
[ \t]+

Result: " ", "\t"

Go regexp · Local WASM
[ \t]+

Result: " ", "\t"

Counterexample

Text "abc"

JavaScript · This browser
[ \t]+

Result: no match

Python re · Local WASM
[ \t]+

Result: no match

PCRE2-8 · Local WASM
[ \t]+

Result: no match

Go regexp · Local WASM
[ \t]+

Result: no match

Recorded by running fixture FX-R11 on : rp.js@1 on Node v24.21.0 (V8), v24.21.0, CPython 3.14.2 (Pyodide 314.0.7), PCRE2 10.48, go1.27.1. JavaScript results come from the rp.js@1 core on Node’s V8; your browser runs the same core.

Engines

Limits