Remove repeated lines from pasted text or text files while keeping the first or last occurrence. Compare lines by exact text or ignore letter case, trim line whitespace, remove blank lines, sort the result, and copy or download the cleaned text directly in your browser.
Input Text
Paste text below or load a text-based file.
Cleaned Output
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Duplicate detection, cleaning, sorting, copying, and downloads happen locally in this browser. Your text is not uploaded to Flipper File.
Remove Duplicate Lines from Text Online
This duplicate line remover scans text one line at a time, removes repeated entries, and keeps either the first or last occurrence. Optional rules can ignore letter case, trim line whitespace, remove blank lines, and sort the final result.
How to Remove Duplicate Lines
- Paste text into the input box or load a supported text-based file.
- Choose whether to keep the first or last occurrence of each duplicate line.
- Set case, whitespace, blank-line, and sorting options.
- Click Remove Duplicates.
- Review the cleaned output, then copy or download the result.
Keep First or Keep Last
Keep First preserves the earliest occurrence of each line and removes later repeats. Keep Last does the reverse: earlier copies are removed and only the final occurrence remains. Unless sorting is enabled, surviving lines stay in the same relative order they had in the source.
Case-Sensitive Duplicate Matching
With case-sensitive comparison enabled, Apple and apple are different lines. Turning case sensitivity off makes
them duplicates while preserving the original casing of the occurrence that
is kept.
Trim Whitespace Before Comparing Lines
The trim option removes leading and trailing spaces and tabs before lines are compared. It also writes the trimmed version to the cleaned output, making it useful for lists where accidental spacing creates apparent duplicates.
Blank Lines
When blank-line removal is off, blank lines participate in duplicate detection just like other lines, so multiple identical blank lines collapse to one. When blank-line removal is enabled, empty and whitespace-only lines are removed entirely.
Sorting the Cleaned List
Sorting happens after duplicate and blank-line processing. This means the tool first determines which lines survive according to your Keep First or Keep Last choice, then alphabetizes those surviving lines.
Text Files and Line Endings
The file loader accepts common text-oriented formats and decodes UTF-8, UTF-8 with BOM, UTF-16 little-endian, and UTF-16 big-endian files locally. Browser textareas normalize displayed line breaks, so LF or CRLF can be selected explicitly for copied and downloaded output.
Private Browser-Side Processing
All line comparison and output generation runs in JavaScript in your browser. Loaded files are decoded locally, and no external deduplication library, CDN script, upload API, or server-side text-processing service is required.