Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Remove exact duplicate sentences from a block of text, keeping the first occurrence of each.
Your result will appear here.
When merging notes from multiple sources, or cleaning up an AI-generated draft, the same sentence sometimes gets repeated. This tool splits your text into individual sentences, and removes any sentence that's an exact match (ignoring case and extra whitespace) of one that already appeared earlier, keeping only the first occurrence.
Paste your text into the input box. The de-duplicated version appears instantly, with repeated sentences removed and the rest re-joined.
The tool reads your text as a series of chunks, where each chunk runs up to and including a period, exclamation mark, or question mark. Any text left at the end without closing punctuation counts as a final chunk. Each chunk is trimmed, then compared with earlier ones after converting to lowercase and collapsing internal whitespace. The first time a chunk appears it is kept; any later match is dropped. The surviving sentences are rejoined with a single space between them.
The comparison includes the ending punctuation. So Is it ready? and Is it ready. are treated as different sentences, and so are Done and Done. because one has no period.
Take this hypothetical text: Backups run nightly. Reports are emailed on Fridays. backups run nightly. Reports are emailed on Fridays! The second sentence is repeated with different casing and the last one uses an exclamation mark instead of a period. The result is Backups run nightly. Reports are emailed on Fridays. Reports are emailed on Fridays! The lowercase repeat of the first sentence is removed, but the last sentence survives because its ending punctuation differs from the earlier one. If you want it removed, change the punctuation to match first.
Use it after merging several sets of notes that overlap, after combining multiple AI-generated drafts, or when a copy and paste accident duplicated a paragraph. Compare the result with the original before publishing, because removing a sentence can leave a paragraph that no longer flows, for example if a removed sentence was the only one connecting two ideas.
Read the cleaned text once from start to finish, check any place where abbreviations appeared, and restore paragraph breaks. For important documents, keep the original in a separate file so nothing is lost if the tool removed something you wanted.
Only exact duplicates (ignoring case and extra whitespace) -- a sentence that's reworded slightly differently won't be detected as a duplicate, since there's no reliable way to judge "close enough" without risking removing sentences that were only superficially similar.
No -- everything runs locally in your browser. Your text is never uploaded anywhere.
No. Sentences are compared in lowercase with internal whitespace collapsed, so the same sentence in different capitalization counts as a duplicate.
Its ending punctuation probably differs, or a word differs slightly. The comparison includes the final period, question mark, or exclamation mark, and it requires an exact match otherwise.
The kept sentences are rejoined with single spaces, so paragraph breaks are not preserved. Add them back manually or process one paragraph at a time.
Yes. A period after an abbreviation or inside a decimal number is treated as a sentence end, which can split sentences and occasionally remove a repeated fragment. Check the output when your text contains these.