WORDCOUNTERS
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ToolRemove Duplicates
Remove duplicate
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100% in your browser · no upload

0 duplicates removed0 unique lines remaining0 total lines in

Remove Duplicates

Remove Duplicates

Line and word dedup · Case + whitespace tolerant · Runs in your browser · no upload

What removing duplicates actually does

Remove duplicate lines or duplicate words from any text. Toggle case-insensitive matching, whitespace trimming, keep-first vs keep-last, and optional alphabetical sorting. Live counts of duplicates removed and unique items remaining. Everything runs in your browser; your text never leaves your device. Free, private, no sign-up.

Two distinct jobs sit under one tool. Line dedup treats every line as one item (the right tool for email lists, URL lists, keyword lists, or a column lifted out of a spreadsheet). Word dedup tokenizes the whole text into words and keeps one of each (the right tool when you want the unique vocabulary of a paragraph, not a row-by-row scrub). The settings change what counts as "the same item": case-insensitive collapses casing variants, trim ignores accidental whitespace, and keep-first vs keep-last decides which copy survives.

  • Line dedup with optional case-insensitive matching and whitespace trimming
  • Word dedup that tokenizes letters and digits (hyphenated compounds count as one)
  • Keep-first or keep-last to control which duplicate survives
  • Optional alphabetical sort applied after dedup
  • Live counts: duplicates removed, unique remaining, total in
Quick answer

Choosing case-insensitive and trim is almost always right for real-world lists (emails, URLs, keywords). Leave them off only when the casing or spacing genuinely matters, like a list of case-sensitive API keys or filenames.

Settings cheat sheet by use case

Six common cleaning jobs, paired with the settings that get the right answer the first time. Pick the row that matches your input and flip the matching toggles in the tool.

Cleaning taskMode + optionsWhy these settings
Email listLines, case-insensitive, trimCollapses [email protected], [email protected] and stray-space copies into one row. Case + trim are essential because email addresses are case-insensitive in practice and exports often include trailing spaces.
URL listLines, trim, sortDeduplicate scraped or copy-pasted URLs. Trim catches lines that imported with whitespace; sorting alphabetizes them for diffing against a reference list.
Keyword listLines, case-insensitiveStrip repeats from an SEO keyword export. Leave case-insensitive on so capitalized variants and exact-match originals merge.
CSV columnLines, defaultPaste one column straight into the box. Default mode keeps case + whitespace exact, so the cleaned column matches what your spreadsheet expects.
Vocabulary listWords, case-insensitive, sortExtract unique words from a paragraph or chapter. Sorting helps you scan for the words you actually want to study; case-insensitive avoids treating sentence-initial words as new entries.
Tag cloud inputWords, case-insensitiveReduce a long body of text to the unique tag candidates before any further analysis. Pair with the keyword-density tool when it ships for frequency-weighting.

Built for cleaning lists fast

Three angles on the same job: what the tool counts as a duplicate, which copy survives, and what to do with the output.

Mint

What counts as a duplicate

  • Whole-line match (default)Lines
  • Token-level match (words mode)Words
  • Optional case-insensitive comparison
  • Optional whitespace trimming on lines
Sky

Which copy survives

  • Keep-first preserves intake orderDefault
  • Keep-last keeps the most recent entry
  • Surviving order always matches input order
  • Sort toggle re-orders alphabetically after dedup
Pink

What you get out

  • Live duplicate / unique / total counts
  • Clean output ready to paste back
  • Lines rejoined with single newlines
  • Words rejoined with single spaces

How to use the duplicate remover

Three steps. No sign-up, no setup, nothing to install.

  1. 1

    Pick a mode

    Lines for one-item-per-line input (emails, URLs, keywords). Words for a paragraph of prose where you want each unique word once.

  2. 2

    Paste and toggle

    Drop your text in the input box. Flip on case-insensitive and trim if the duplicates differ in casing or stray spaces. Pick keep-first or keep-last as the situation demands.

  3. 3

    Copy the result

    Read the stat line (X duplicates removed, Y unique remaining), then hit Copy to grab the cleaned list. Use Clear to start a new run.

Who built this

Same team behind the Word Counter, Character Counter, Sentence Counter, and Case Converter. Every tool on this site runs entirely in your browser.

The WordCounters team

Linguists, editors & engineers

A small team of writers and engineers shipping privacy-first text tools. Duplicate detection uses a stable Set-based comparison with optional normalization (lowercasing for case-insensitive matching, trim for whitespace tolerance), so the result is deterministic for the same input + settings.

✓ Method documented✓ Updated May 2026✓ Privacy-first✓ Free · v1.0

Frequently asked

Direct answers; mirrored in this page's FAQ JSON-LD so AI answer engines can cite them cleanly.

What does removing duplicates do?
It scans your input, identifies items that appear more than once, and emits a clean version with each unique item kept only one time. This page offers two modes. Line mode treats every line as one item (used for email lists, URL lists, keyword lists, spreadsheet columns). Word mode tokenizes the whole text into words and keeps one of each (used for vocabulary lists, tag-cloud inputs, content audits). Live counts show how many duplicates were removed and how many unique items remain.
What is the difference between line dedup and word dedup?
Line dedup compares whole lines. Two lines are duplicates only if their entire content matches (subject to the case-insensitive and trim toggles). Word dedup ignores line breaks entirely, extracts every word from the input (runs of letters and digits, with internal hyphens and apostrophes preserved), and keeps one of each. Line dedup is for one-item-per-line lists; word dedup is for prose where you want the unique vocabulary.
Should I turn on case-insensitive matching?
Yes for most real-world lists. Email addresses are case-insensitive ([email protected] and [email protected] point to the same mailbox); SEO keyword exports often capitalize the first letter of one variant; sentence-initial words and mid-sentence words match in word mode. Leave it off only when casing is significant, such as case-sensitive identifiers, API keys, or filenames on case-sensitive filesystems.
What does the trim option do, and when do I need it?
Trim ignores leading and trailing whitespace when comparing items. It only applies in line mode (word mode already trims because the tokenizer skips whitespace). Turn it on when your input was pasted from a spreadsheet or scraped from a page that left stray spaces or tabs at the end of some lines. Without it, "foo" and "foo " (with a trailing space) are treated as different items.
What is the difference between keep first and keep last?
If your input has the same item three times, only one copy survives. Keep first preserves the earliest occurrence and drops the later ones; keep last preserves the most recent and drops the earlier ones. The surviving order always matches the input order, so keep last is useful when later entries supersede earlier ones (e.g. a log where the last status for an ID is the current one).
Is my text uploaded anywhere?
No. The duplicate remover runs entirely in your browser. We don't upload, log, or send a single character to any server. Your text is held in your browser's per-tab session storage so a refresh doesn't lose your work, and it clears the moment you close the tab. The page itself is static HTML; the deduplication is a small client-side script. Closing the tab is the only privacy guarantee you ever need.

Try the rest of the tools

Same brutalist console, same privacy promise. Pick a tool:

Word CounterCharacter CounterSentence CounterCase ConverterAll tools