Remove Duplicate Lines
Remove duplicate lines from any list or text instantly. Options for case-insensitive matching and trimming whitespace. 100% private, runs in your browser.
Last reviewed by the Radiatus Cloud team
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Deduplicate a list without reordering it
Pasting a list and needing only the distinct entries is a constant small task: merged email lists, combined log files, exported tags, concatenated CSV columns. This tool keeps the first occurrence of each line and drops every later repeat, so the order you pasted is preserved rather than sorted. That matters when the sequence carries meaning, such as a ranked list or a chronological export.
The options decide what counts as a duplicate
Two lines that look identical to you may differ by a trailing space or a capital letter, and whether those count as the same line is a judgement only you can make. Case-insensitive matching treats Apple and apple as one; trimming each line first ignores leading and trailing whitespace so " item" and "item" collapse together. Turning both off gives an exact, byte-for-byte comparison, which is the safe default when the text is code or data where whitespace is significant.
Blank lines are handled deliberately
A long run of blank lines is usually noise, but sometimes the spacing is intentional. The keep-blank-lines option lets you decide whether empty lines are deduplicated along with everything else or preserved as written, so you are not forced to lose formatting to remove repeats. Everything runs in your browser, so even a large paste stays on your machine.
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Frequently Asked Questions
Does it keep the original order?
Yes. The first time each line appears it is kept in place, and later duplicates are removed. The remaining lines stay in the order you pasted them rather than being sorted.
How do I treat differently-capitalised lines as duplicates?
Turn on case-insensitive matching. Then Apple, APPLE and apple are treated as the same line and only the first is kept.
What does trimming each line do?
It ignores leading and trailing spaces and tabs when comparing, so a line with accidental indentation is recognised as a duplicate of the same text without it.
Are blank lines removed too?
Only if you want them to be. The keep-blank-lines option preserves intentional spacing; otherwise blank lines are deduplicated like any other line.
Is there a size limit?
Only your browser memory. The deduplication runs locally in JavaScript, so nothing is uploaded and reasonably large lists process instantly.
Privacy & Security
All processing happens locally in your browser — your text is never uploaded.
How to Use
Paste your list, choose options, and duplicates are removed automatically. Copy the cleaned result.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
Related Tools
Emoji Picker & Copier
TextBrowse, search, and copy emojis by category. Collect multiple emojis and copy them all at once. Recently used emojis saved locally.
Text to Speech Player
TextConvert text to natural speech using the Web Speech API. Adjustable voice, speed, pitch, and volume with playback controls.
Speech to Text Transcriber
TextTranscribe speech to text using your microphone. Supports multiple languages with continuous listening, copy, and download features.