Remove Duplicates
Remove duplicate lines from your text instantly. Choose between case-sensitive or case-insensitive duplicate detection.
Paste or Upload Text
Quick Copy
Case-Sensitive
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Case-Insensitive
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Remove duplicate lines from your text instantly. Choose between case-sensitive or case-insensitive duplicate detection.
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A duplicate line is a line of text that appears more than once within the same document. Duplicate lines commonly show up in exported data — think email lists pulled from multiple sources, log files that repeat the same event, CSV rows accidentally exported twice, or notes copied and pasted several times into the same file.
Left unchecked, duplicate lines inflate file size, skew counts and statistics, and can cause real problems downstream — duplicate email addresses trigger repeat sends, duplicate log entries hide the true frequency of an event, and duplicate rows in a spreadsheet throw off totals and aggregations.
A Duplicate Line Remover scans a block of text line by line and strips out every repeated occurrence of a line, keeping only the first time each one appears. The original order of the remaining lines is preserved — nothing gets sorted or reshuffled, so your list stays in the same sequence you started with, minus the repeats.
This tool processes your text entirely in the browser and produces two results side by side: a case-sensitive version (where "Apple" and "apple" count as different lines) and a case-insensitive version (where they count as the same line and only the first one is kept). You can optionally strip blank lines before deduplication, paste text directly or upload a .txt/.md file, and copy either result with one click.
Paste your list into the text area, type it directly, or upload a .txt or .md file using the upload panel below the textarea.
If your text contains blank lines you don't want counted, check "Remove Empty Lines" so they're excluded before duplicates are detected.
The stats panel shows how many lines you started with, how many are unique, and how many duplicates were found, updated live as you type.
In the Quick Copy sidebar, choose the "Case-Sensitive" result if "Apple" and "apple" should be treated as different lines, or "Case-Insensitive" if they should be treated as the same line.
Click "Preview" on either result to open a larger modal view of the full deduplicated text before deciding which one to use.
Click the copy icon next to the result you want (or "Copy & Close" from the preview modal) to copy the deduplicated text to your clipboard.
In the case-sensitive result, "Apple", "apple", and "APPLE" are all treated as different lines and none of them get removed. If your data isn't consistently cased, use the case-insensitive result instead.
A line like "banana" and "banana " (with a trailing space) are not identical, so they are treated as two different lines even though they look the same. Trim stray spaces in your source data before pasting if this matters.
The case-insensitive result keeps the exact text of whichever occurrence appeared first — it does not force everything to lowercase or uppercase. If "APPLE" appears before "apple" in your list, "APPLE" is what survives in the output.
This tool preserves the original order of your lines — it does not alphabetize or otherwise sort the result. If you need a sorted list, run the output through a separate sorting tool afterward.
Multiple empty lines in your input are themselves duplicates of each other and will collapse to a single blank line unless you enable "Remove Empty Lines" to strip them entirely.
This tool only removes exact duplicate lines. Lines that are similar but not identical — such as "John Smith" and "John Smith" (double space) or "New York" and "New York, NY" — will both be kept since they are not exact matches.
A mailing list merged from two sources with a mix of case and exact repeats.
Input
alex@example.com jordan@example.com Alex@example.com sam@example.com jordan@example.com
Output
Case-sensitive: alex@example.com, jordan@example.com, Alex@example.com, sam@example.com (4 lines — "Alex@" differs from "alex@") Case-insensitive: alex@example.com, jordan@example.com, sam@example.com (3 lines — "Alex@example.com" merged into the first occurrence)
Repeated log entries from a retry loop, with order preserved.
Input
Connection established Timeout, retrying... Timeout, retrying... Connection established Request completed
Output
Connection established Timeout, retrying... Request completed
A short word list with stray blank lines, using the "Remove Empty Lines" option.
Input
apple banana apple cherry
Output
apple banana cherry
No. This tool runs entirely in your browser. Your text never leaves your device or gets sent to a server.
The case-sensitive result treats "Apple" and "apple" as two different lines and keeps both. The case-insensitive result treats them as the same line and keeps only the first one it encounters.
No. The order of your original lines is preserved. Only repeated lines are removed — nothing is reordered or alphabetized.
The first occurrence of each line is always kept; every later repeat of that same line is removed.
Yes. A line with a trailing or leading space is technically different from the same line without it, so it won't be recognized as a duplicate. Clean up stray whitespace beforehand if this could affect your results.
When enabled, blank lines are filtered out of your text before duplicates are detected, so they don't get counted in your statistics or collapse into a single empty line in the output.
You can upload .txt or .md files. The contents are loaded directly into the text area for deduplication.