Data & Formatting · In-Browser Regular Expression Lab

Duplicate Words Regex — Find and Remove Consecutive Repeated Words

Finds repeated words separated by whitespace like 'the the' or 'is is' using backreferences.

Pattern:

Regular Expression Pattern & Flags

Flags:

//gi

Live Test String

Match Found

Load Sample:

Match Inspection & Details1 match

Match #1:the the

Test Samples Verification Matrix

Expected Valid Samples (Should Match)

the the company Pass

this is is great Pass

we we went Pass

Expected Invalid Samples (Must Reject)

the company Rejected (Pass)

this is great Rejected (Pass)

very good Rejected (Pass)

Code Implementation Generator

// JavaScript / TypeScript (ES6+)
const pattern = /\b(\w+)\s+\1\b/gi;
const text = "the the company";

const isMatch = pattern.test(text);
console.log("Is Match:", isMatch);

if (isMatch) {
  const matches = text.match(pattern);
  console.log("Matches:", matches);
}

Regular Expression Token Breakdown

Captures a word with `(\w+)` and checks if it is immediately followed by the exact same word via `\1`. Each component of the regular expression serves a distinct syntactical purpose as mapped below:

Token Pattern	Name / Component	Function & Rule
\b	Word boundary	Prevents partial word matches.
(\w+)	Word Group	Captures word characters into group 1.
\s+	Whitespace	One or more spaces or linebreaks.
\1	Backreference	Matches the exact contents of group 1.