DuckyTools
Home Text Duplicate Word Finder

Duplicate Word Finder Text

Catch accidentally repeated words — the the, and and — that spellcheckers walk straight past.

Duplicate Word Finder is a free online tool that catch accidentally repeated words — the the, and and — that spellcheckers walk straight past. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.

Price
Free — no account, no quota, no watermark
Category
Text
Where it runs
In your browser, on your device
Files uploaded
None
Technology
plain JavaScript
Settings
3
Works offline
Yes, after the first visit

About Duplicate Word Finder

A doubled word is the one typo a spellchecker cannot catch, because both words are spelled correctly and the grammar checker often treats the pair as valid. It survives every read-through because the eye supplies what it expects rather than what is on the page — which is precisely the job to hand to a machine.

How to use it

  1. Paste or type your text. Every figure recalculates on each keystroke.
  2. Use the sample button to see what the numbers look like on real prose.

The 3 settings

SettingWhat it doesDefault
Ignore caseOn or off. On by default.On
Look across line breaks tooOn or off. On by default.On
Remove the duplicates in the outputOn or off. On by default.On

Under the hood

Runs onplain JavaScript — runs the whole thing
ControlsIgnore case, Look across line breaks too, Remove the duplicates in the output

Questions

Why are some doubled words skipped?

Because a few genuinely double in English. "Had had" is the past perfect of "have". "That that" is correct in sentences like "the fact that that happened". Flagging them produces the false positives that get a proofreading tool switched off, so a short allowlist covers them.

Does it look across line breaks?

By default yes, since a word doubled across a wrapped line is the hardest kind to see. Turn it off if you are checking a list where the last word of one item and the first of the next legitimately repeat.

Will it catch other repetition problems?

No — this is specifically adjacent identical words. Overused vocabulary across a whole document is a different problem; the Word Frequency Counter is the tool for that.