Overview
Introduction
Accidental repeated words, from copy-paste mistakes, merged documents, or duplicated tag lists, are a common cleanup task that's tedious to fix by hand across a long passage.
It runs entirely client-side, so nothing you paste is ever uploaded to a server.
What Is Duplicate Word Remover?
A cleanup tool that removes repeated words from your text, matched case-insensitively, keeping only each word's first occurrence while preserving the original order and spacing of what remains.
It runs entirely client-side as part of this site's String Tools collection, so nothing you paste is ever uploaded to a server.
How Duplicate Word Remover Works
The text is split into alternating word and whitespace tokens, and each word token is lowercased and checked against a set of words already seen.
The first time a word appears it's kept and recorded; every later occurrence of the same word is dropped along with the whitespace immediately before it, so the remaining text doesn't end up with double spaces.
When To Use Duplicate Word Remover
Use it to clean up an accidentally duplicated word in a sentence, deduplicate a comma-free list of tags or keywords, or tidy text merged from multiple sources.
It's a fast way to get the answer without opening a code editor, a REPL, or writing a one-off script just to check.
Often used alongside Find & Replace Tool and String Length Counter.
Features
Advantages
- Case-insensitive matching catches duplicates regardless of capitalization.
- Preserves the original order and spacing of the words that remain.
- Drops the whitespace that preceded a removed word along with the word itself, so no double spaces are left behind where duplicates used to be.
Limitations
- Treats a word plus its attached punctuation as one token, so 'word' and 'word,' aren't currently merged as duplicates.
- Not a semantic deduplication tool; it only catches exact repeated tokens, not synonyms or paraphrases.
Examples
Best Practices & Notes
Best Practices
- Run Find and Replace first if you need to normalize punctuation before deduplicating, since punctuation is currently part of the word token.
- Read the result through afterwards, since legitimate repetition such as 'had had' or 'that that' is removed alongside the accidental kind.
- Prefer it for tag and keyword lists over prose, because repeated words in a list are far more likely to be genuine mistakes.
Developer Notes
The implementation splits on `/(\s+)/` to keep whitespace as separate tokens in the array, tracks lowercased words seen so far in a `Set`, and when dropping a duplicate also pops the preceding whitespace token off the result array if present, avoiding a manual re-join with `' '` that would collapse original spacing everywhere.
Duplicate Word Remover Use Cases
- Cleaning up an accidentally repeated word in a sentence
- Deduplicating a plain list of tags or keywords
- Tidying text merged from multiple sources with overlapping words
Common Mistakes
- Expecting 'word' and 'word,' to be merged as the same token; punctuation is currently part of the comparison.
- Assuming this performs semantic deduplication of synonyms rather than exact repeated words.
Tips
- Trim trailing punctuation from words beforehand if you want punctuation-insensitive deduplication.
- Deduplication applies across the entire text rather than just to adjacent words, so a word repeated in a much later sentence is dropped too.